The official recognition is hugely gratifying, she says, even though most of the time she's recognised, it's for the Whittaker's chocolate ads.
She's also known for her style. Before devoting most of her energies to motherhood, she and Borich were frequently snapped in the social pages - Elliott also did a stint as fashion editor at Real Groove magazine.
Yet in Bliss she puts on a plummy voice and dons Victorian garb to inhabit Mansfield as she embarked on her literary and sexual adventures in Europe, much to the chagrin of her family.
The first scene sees Elliott with a huge grin, sprinting in excitement.
"Something that grew in me while I was playing her was this, like, lust for life. I felt excited about waking up in the morning. I've played so many depressing characters, dark roles, dark girls and tortured souls that it was nice to play someone who was, like, hyped on life. I'm not smoking cigarettes in the back of an alleyway somewhere, eh?"
It's not the first time she has played Mansfield. In 2005 she went to Berlin for short film An Indiscreet Journey, based on Mansfield's affair with a soldier.
Bliss, with $2.8 million funding from NZ On Air, is written and directed by Fiona Samuel and directed by Michele Fantl, the team behind Piece of My Heart with Emily Barclay and Annie Whittle. This version of Mansfield is alive, exuberant and youthful - she can't wait to head overseas. The TV drama finds the young Mansfield hungry to experience travel, love, sex - the stuff that informs her best work.
"Oh my God, I love women like that," says Elliott. "If I see a girl like that I'm like, 'you're f***ing cool, let's be mates', which is usually trouble. When I pick best friends they all have that certain quality. A rebellion, a spark, a fieriness, a drive, some ambition."
Elliott exudes all of these qualities, but they're tempered by a relaxed, 'seen-it, done-it' attitude. At 29, she has travelled, taking off to Barcelona and Tokyo in her early 20s, going to foreign film festivals for Fracture and Toy Love and embarking on a three-month stint in Los Angeles last year with Borich. During that trip she auditioned for TV pilots and recalls showing up to one audition with a room full of identical actresses. "I guess we all got the memo then," she deadpanned, her Kiwi humour falling on deaf ears.
Elliott has an uninhibited manner on and off camera. Recently she had to sit her full driver's licence before heading to the US. The driving instructor asked what she did for a living. When she said she was an actress, he asked if she'd been on Shortland Street.
"I said no, and he was like, [her voice gets so loud it startles the dog in the raincoat: 'I LOOOVE Shortland Street!'
"I was like, 'but I've been in lots of things, I'm an award-winning actress. Haven't you seen my films?"' It's clearly intended as a bit of luvvie-mocking.
Kate Elliott originally wanted to be a visual artist like her parents. Her mother, Moira Elliott, a former potter, is now a curator who works all over the world, recently working on a ceramic exhibition in Taiwan. Her Japanese stepfather, Haruhiko Sameshima, is a photographer who works with large, old-format cameras. He has helped bring up Elliott since she was 2 "and he is the coolest person I've ever met in my entire life. Even cooler than Milan."
Her biological father, Gary Elliott, is also in her life. He is a teacher at King's School and has two other children, Tyler and Frances, who she sees regularly.
Elliott had a happy childhood. At age 8, inspired by a trip to Universal Pictures in LA, she decided she wanted to be an actress. She excelled in art and drama classes at Epsom Girls Grammar School, becoming a prefect of arts and culture. Her drama teacher coached her through her first role, at the age of just 14, as a bulimic girl in a Montana Sunday Theatre production. That was House of Sticks, written by Steven Zanoski, who is now a producer at Shortland Street.
"She blew me away. I knew we'd found a huge talent," he says.
"It's so absolutely rare to find a 14-year-old with so much maturity. It was a hard-going script about sexual abuse. For a first-time actor she had an extraordinary emotional range."
Even a TV Guide People's Choice nomination for best actress didn't sway Elliott from her plans to study at Elam. Then, straight out of school, she got a part on the TV series, Street Legal. It was there she met Borich, a child actor years before he made his name as frontman of Pluto.
That led to more work, on US productions Xena and Cleopatra 2525. There was no formal acting training, no treading the boards. Instead, Elliott got an education on the technical aspects of film, television - and herself.
"I'm aware of my emotions all the time, which is good for being an actor, and sometimes kind of intense. I am conscious of myself. What makes you do things and cognitive behavioural stuff really interests me. I like therapy. Therapy's how I nut out a character. I'm into it.
"I'm not doing it at the moment but I have done it before. Just trying to figure out why you do something, where you come from and what it means and how it makes other people perceive you. What you give off and what you get back."
How does she think others perceive her? "When people meet me they're like, 'oh, you're actually quite nice. I expected you to have tattoos and lots of piercings'."
Still, she wonders if she can be too acerbic. During Insiders Guide, she proudly recalls a reporter describing her as being "notorious to interview". Elliott played the unpredictable and moody Nicole and it seemed her character was rubbing off. After the shoot she had to apologise to cast-mate Gareth Reeves.
"I think a few of [the cast and crew] thought I was such an arsehole. She got inside me a bit. I have a habit of taking on a whole lot more of the character than perhaps I should. It happened with Katherine. It would be good if I could play like, happy, awesome positive people all the time but I'm pretty good at the dark ones."
Reeves says he doesn't remember anything that would warrant contrition from his co-star. He'd worked with Elliott in 2007, on an animated series that never made it to air here, and worked with her again on the TVNZ drama series, The Cult, not long after she'd had Dee Dee.
Reeves was also in LA with Elliott and Borich at the same time, and went to a Kiwi barbecue they hosted, where he recalls being impressed by the intelligent conversation - and the asparagus rolls.
"There were a few times I remember being on the end of some barb," he says. "She can kill you with a look, that girl. One arched eyebrow and you wither. She's got a highly developed bullshit radar, which is probably what makes her a good actor. She has softened a bit since Dee Dee came along. She's such a flippin' pussycat. She has a huge heart but doesn't suffer fools."
He also says Elliott gives herself a hard time, something the actress agrees with. She takes every role seriously, and wants to be good.
Elliott's predilection for the darker roles comes from understanding what it's like to be in a dark place. She suffered pre-natal depression while carrying Dee Dee, and had a difficult pregnancy, where she put on 30kg. Before she fell pregnant (and yes, her daughter is named after the "sad, old junkie" Ramone), Elliott liked to party to excess.
Borich himself was no stranger to the lifestyle. His hard-drinking sessions with his Pluto bandmates were legendary. Elliott was drawn to his "rock 'n' roll" attitude. The difference was that the petite actress didn't have the constitution for living like a rock star. She'd push herself, drinking and taking drugs, a lifestyle that started off as a bit of experimentation and developed into an unhealthy habit.
"I love new experiences. That's what drives me and gets me into trouble and what makes me 'me'. But when [drug use] starts to define you, it's really frightening ... I guess I never realised there was an alternative way of living that might mean I had a more fulfilling life."
She won't be drawn on the details except to say she'd never been much of a drinker - giving that up was more a case of proving to herself she had discipline.
But recognising her desire for a physical buzz of some kind, she soon found her new drug of choice: exercise. Like her biological father, who ran marathons, she now runs 7km every day and boxes three times a week. She's also interested in helping others to "not be where I was and make more positive choices for their lives". That includes being a positive role model for her 19-year-old half-sister Frances, whose mother died four years ago. It works both ways, she says. Frances gives her another reason to be healthy and happy.
"What do you get from abusing drugs and alcohol? Because if you're going to do something bad to yourself, whatever it is, there's got to be a reason behind it. And I guess what I got out of it is a release, an escape or a blow-out. I'm learning that I can find that release through other avenues. I get super-high on endorphins after I've worked out. And those are the best things to get high on, in my opinion." She stops, looks coy through her long lashes.
"It's so embarrassing. Who would've thought, eh? Me running up Mt Eden ..."
Fiona Samuel describes the Bliss role as a naughty, mischievous character. But she didn't even have Elliott on her radar when she was casting, having seen her in punky-looking, wicked roles. Then she saw Elliott's "gripping" audition, telling Bliss' resident literary scholar Vincent O'Sullivan she'd found her Katherine "and she was small and dark and has a mysterious feline quality".
"She is so vital and sparky and engaging and provocative. She has a face that changes like the weather. She can look very young, at times she looks like she's been around the block 100 times. I really found Kate so intriguing."
Elliott was just as keen on the role. She'd already read a lot about Mansfield from the last time she played her.
This time she concentrated on the journals and love letters between a 19- year-old Mansfield and her young lover, Garnet, discovering a deeply passionate, flawed woman, fuelled by her emotions.
Samuel is no stranger to working with actors, some of whom need a bit of corralling into feeling comfortable enough to let their guard down. Not Elliott.
"She will do anything. She's quite a bold creature. I think of her as a racehorse. I thought, 'ooh, I've got a real live one here'. Some actors can be very insecure about the process. Others, like Kate, are just fearless - the more difficult the task you give them, the more excited they get."
One scene, eventually cut, entailed Elliott running down a slippery, wet hill as she was drenched with hoses. She had to do it 10 times to get the shot.
"Every time she'd hike up that hill, ready again. She said she actually really enjoyed it."
Another, shot in wintry August, sees Elliott sprint naked into the ocean, with an impressive disregard for her glamour, says Samuel. In another nude scene, Mansfield loses her virginity, the actress surrounded by 40 crew and a camera in her face.
Elliott is just as up-front when, a few weeks later, news filters through that the LA move is off.
"Shit kinda blew up," she explained on the phone. "Crappy life shit."
After five years of marriage, Elliott and Borich decided to split. He came home from LA to act in the New Zealand version of Underbelly, and so they could sort out the logistics of the break-up, primarily custody of Dee Dee. This would be painful for anyone but for Elliott it was particularly bad timing, coming right in the middle of her promotional duties for Bliss, forcing something otherwise private into the open.
"Obviously these kind of things are not cut-and-dried and especially not with me and Milan," she says. "What I do know is I love Milan unconditionally and I always will and he's a wonderful father and very talented. He should be in LA and so should I - and I know that I want Dee Dee to be with him because she misses him a lot. But whatever happens with us in the future is up in the air."
It's our second meeting and the gloves are off. So are the heels. Elliott appears serene, fresh from a six-day yoga retreat in Fiji. She's decided to go to LA after all, mainly for Dee Dee's sake. Also for her own, so she won't regret not going.
"I don't know what will happen. But [being apart from Milan] has been really good for me, and I'm making really conscious, positive decisions for myself for the first time in a long time and learning to really enjoy the little things and take time for myself. It sounds a bit like a midlife crisis but it's not."
There's a silver cloud career-wise, too. Before she decided to stick with her US plans, Elliott auditioned for a part on Shortland Street and got it. A subtly comedic role playing a gothic Romanian bride called Zlata had come up. It ticked all the boxes: it would play to her dark strengths but with the levity she craved. And it was only for four months.
"It was sheer luck. I really need some money and I wanted to do something interesting. I get a lot of gothic, vampiric roles but this is funny. The writers have done a really good job."
Zanoski, who'd first encountered a teenaged Elliott 15 years earlier, admits he was surprised to see Elliott's name on the audition tape.
"I wasn't sure she'd be interested in doing Shortland Street. She's an actor in high demand."
The show runs at quite a pace and Elliott found it difficult to find her rhythm.
But Zanoski was charmed by her convincing Romanian accent and the way she picked up on the character's funny nuances. Elliott arrives on screen soon as Luke's new fiancee - and throws the rest of the characters into a spin.
"It was interesting to watch her transform herself from this very affable and collegial actor into this crazy Eastern European woman."
There's a strange irony in all this, playing a new bride as her own marriage falters; starring in a drama called Bliss at a less-than-blissful time.
But Elliott has a newfound strength.
"I feel fantastic," she says.
"I was almost feeling guilty about feeling really good, which is stupid. But no, I'm good."
Bliss is on TV One tomorrow at 8.30pm.
