Lady Kitty Spencer is the daughter of Charles Spencer and niece of Diana, Princess of Wales. Photo / Getty
We have long since stopped expecting a Lady to look like - well - a lady. But in the case of Lady Kitty Spencer, hailed on the cover of this month's Tatler magazine as "Diana Princess of Wales' most ravishing niece", we have a Lady who is a bona-fide bombshell. Lips parted to show a Bardot-esque hint of bite, she is all tousled bed-hair, glowing skin and traffic-stopping cleavage.
Indeed, the photos inside the magazine show her Sloane bosom barely restrained by the designer gowns she models. Not for nothing does younger sister Amelia call her by the vulgar nickname 't**s'.
Her father Charles Spencer - the 9th Earl who has a reputation as one of the least charming men in the UK - was said to be furious with this latest piece of media stardom.
"They had a really big row about it a few weeks ago," the Daily Mail was told, although a representative of the family strongly denied the fight occurred. But, bluster as he might, it doesn't seem anything is going to stop 24-year-old Kitty, his eldest daughter, from striving to become famous in her own right.
And she has the looks, connections and money-making media savvy to do just that. Move over Pippa Middleton, there's a glamorous new star in town.
Professionally, she is represented by Paula Karaiskos, who also looks after Kate Moss at the Storm model agency.
She has one dainty foot in the party-hard London scene, via a close friendship with leggy Lady Violet Manners, 22, the Duke of Rutland's daughter. These two and Violet's younger sister Alice can be found in bars like Loulous in Mayfair, and at high-end parties around Europe.
Kitty's also on warm terms with her cousins Prince William and Prince Harry, but not in the inner circle of either.
Kitty and her equally striking two sisters first grabbed Britain's attention when they attended William and Kate's wedding in 2011. Indeed, with her golden hair and big blue eyes, Kitty bears a real resemblance to Diana. But any mention of this seems to be met with blushes. "Gosh, if you think that then I am really happy," she told one interviewer.
And while she might not dine out on this royal link - she says she only has "happy memories" of Diana - there is no doubt that Lady Kitty is making waves in London.
"Kitty is one of the most eligible women in London," a source said. "She is not one of these super discreet, rather dull members of the royal circle, she is warm and fun. She is really enjoying being the centre of attention."
Lady Kitty is also close to a number of the crowd from reality TV show Made in Chelsea, having been to prep school with former cast member Amber Atherton. Like her telly pals, she seems happy to accept freebies in exchange for plugging products on social media.
Indeed, unless she is just exceptionally grateful by nature, there is evidence of this unseemly trade-off all over her Instagram account, which has 10,400 followers.
When she goes to a party, she routinely thanks a hairdresser, stylist, make-up artist, whoever supplied the designer clothes, and invited her.
"Thank you for my blow-dry!" she will exclaim. "Love my beautiful @CaratLondon jewellery" and so on.
A recent trip Downunder for the Melbourne Cup came courtesy of Emirates, who sponsored the horse race. Lady Kitty mentioned the airline on all her Instagram posts for several days of her holiday.
Add to this her habit of charming well-connected millionaires, and you have a young woman who seems very canny indeed.
Pictures of Kitty beaming at parties with middle-aged rich men - typically a mix of fashion designers and businessmen - are a staple of her social media account.
But the happiest news for potential suitors is that she is single.
She had a year-long romance with Italian property tycoon Niccolo Barattieri di San Pietro, 44, but that ended four months ago.
Earlier this week she was pictured frolicking on Bondi Beach in Sydney with handsome Australian weatherman James Tobin, 35. A local magazine quoted a source saying: "They're crazy about each other".
Her friends, however, think she remains unattached.
Another previous boyfriend was the England cricket legend Denis Compton's grandson Nick, also a cricketer, but they split in 2013.
Kitty told Tatler: "I'm very sentimental. I have only had a couple of boyfriends."
In due course, however, she would like to be married at the 13,000-acre ancestral seat, Althorp House, in Northamptonshire.
She was born in Britain to Earl Spencer, younger brother of Diana, and British model Victoria Lockwood. In 1995, when Kitty was 4, the family - seeking a fresh start and sunshine - moved to South Africa.
There are three sisters: Kitty and twins Eliza and Amelia, 23. The heir to the £100 million ($230 million) Althorp estate is brother Louis, 21. Kitty has insisted she has no qualms about her brother inheriting, saying primogeniture is the "correct way".
Not long after they moved to South Africa, Princess Diana died. Soon after came Earl Spencer's very bitter and public divorce from Victoria, where he was branded a philanderer while her anorexia and drug addiction were laid bare.
Kitty's father later married former teacher Caroline Freud, the ex-wife of PR guru Matthew Freud, and they had two children before the marriage failed. In 2011, he got married again, to Canadian divorcee Karen Gordon, and they have a daughter.
Kitty and her siblings were raised by their mother on a gated estate in the affluent Cape Town suburb of Constantia. Their father flew out every month or so. By this stage, Victoria had fallen for a handsome charmer named Jonathan Aitken (not the Tory ex-Cabinet minister).
She was attending a rehab unit having been clean of drugs for some years, and he was trying to beat an addiction to cocaine. They had a son, Samuel, in 2003 and were married two years later, but in 2009, that marriage also failed when Aitken relapsed.
Amid these dramas, Earl Spencer moved his children into a guesthouse and later rented a mansion, hiring staff to take care of them.
By this time Kitty was studying psychology and politics at the University of Cape Town, and happily took on an almost maternal role. Victoria is now a psychologist and addictions counsellor and is extremely close to her children.
Kitty once told the Daily Mail she speaks to her mother - whom she calls "Mumcat" - up to five times a day. She proudly describes her mother as a "brilliant" counsellor who has done such a good job on her that she has never even tried a cigarette.
Kitty is also noted for her commendably healthy attitude towards her figure. She claims to have never even owned a set of weighing scales.
Nearly four years ago Kitty moved to the UK, studying for a business masters degree in London. Then she took up a job with Give Us Time, a charity that matches soldiers in need of a family holiday with timeshares and holiday homes owned by British families. The charity is the brainchild of former Defence Secretary Dr Liam Fox.
Kitty has a very warm relationship with her father. A friend says simply: "She clearly loves him, just like girls do with their dads."
There is a fortnight in July when the whole family gathers at Althorp. "We don't notice the 'steps' and 'halves', we are all just brothers and sisters," said the friend.
Kitty's is a gilded lifestyle that sees her nearly rival globe-trotting Princess Beatrice for holidays.
It has been noted that Lady Kitty, who has a flat in Fulham in Southwest London, has been on seven holidays in the past seven months.
These include trips to Ibiza, St Tropez, Milan, Florence, Capri, Melbourne and Cape Town, where her mother still lives, along with her sisters. Apparently, she is due in South Africa for a Christmas visit.
But it is unlikely to be all play and no work over the party season - Kitty is surely going to milk her moment in the sun.