And over the past year especially, with songs like the breezy chinking reggae groove of her debut single You'll Never Take That Away ("I didn't know I could write reggae songs so I was like, 'Yes', and I'm a big Bob Marley fan too.") and the poptastic country of Rewind, she has started making an even bigger name for herself.
She's also done a number of covers, including a rendition of Lonely Boy by the Black Keys ("I tried doing a sad version of it ... you'd probably hate it.") and most notably she entered her version of One Direction's One Thing in Perez Hilton's Can You Sing? competition and got an honourable mention from the influential US blogger.
She releases her debut album, Six Strings and a Sailboat on November 16 and the same day supports American one-man synth pop machine Owl City at the Powerstation.
McDell, who lives in Auckland during the week and heads home to the northern surf town of Mangawhai at weekends to hang out with her family, is tall and striking, but befitting her beach bum, ocean-loving status, is dressed casually in a T-shirt and jeans when TimeOut meets her at a cafe.
She's slightly awkward, as someone just out of their teens might be, but speaks openly and confidently about where she's at and what her plans are.
She's the first to admit she's a little green - naive even - when it comes to making music and the whole business of it. She laughs as she recalls how she wrote so many songs during her mid-teens that her parents said to her "maybe you should go and play them to people".
"But," she smiles, "we didn't really know what to do. What do you do when you've got some songs? And at that time YouTube wasn't as big a thing as has become in recent years, so we went to see a record label [EMI] and gave it a shot - and luckily it's worked out really well."
Though she's prolific, and says songwriting comes naturally to her, she still doesn't rate herself as a "proper musician" just yet.
Going into York Street studios in August to record the album with a band brought that home to her.
"I try to be confident, but working with amazing musicians in a studio I don't feel like I'm up there yet. I'm getting there though," she says.
Even though McDell comes from a generation where the album is not a format coveted by young music fans, she rates Six Strings and a Sailboat as "the most amazing thing I've achieved so far in my life".
Then again she's not pinning all her hopes and dreams on making it in the music business and becoming New Zealand's answer to Taylor Swift.
"But to grow up and be able to say, 'I had an album', to my kids, that's quite special to me. And they are all originals," she says proudly.
"My love and passion is songwriting, not to become famous, and if I can write songs forever then I'll be happy. And because I haven't dedicated my entire life to being a musician I am ready for what is coming up because it's not everything to me. I'm not relying on it completely. There are so many other parts of my life."
She is currently doing a graphic design degree at university, is an avid diver and surfer, and comes from an ocean-loving yachting family. When she was 7 her mum and dad packed the family up and set off on a two-year jaunt on a yacht around the Mediterranean.
"We were at the age where it wasn't too important for us to be at school ... well that's what Dad thought anyway," she laughs. "His spirit is like mine. He's not meant to be in an office."
There's a line on Stick With You that goes "a drink and the sunset and I'm there" that might just sum up McDell's carefree, laid-back approach to life.
"I've always appreciated the simpler things in life. That song is inspired a lot by my mum, because she's quite a hippie," she laughs.
But she says the banjo-driven All I Need is probably the song that sums her up best with lines like, "Someone stole my how to live plan, but my head says, what the hell, man."
And she also wants to use her music to do her bit for raising awareness of issues surrounding the world's oceans, even if that means walking the red carpet at the New Zealand Music Awards in a shark costume like she did last week as a protest against shark finning.
As she says, she's "doing it for the ocean".
Who: Jamie McDell, singer-songwriter
Debut album: Six Strings and a Sailboat, out November 16.
Where & when: Supporting Owl City, Powerstation, November 16.
-TimeOut
