Mitchell, who is now based in Los Angeles, grew up in Lismore in New South Wales, and says she had no idea Teen Beach Movie - which airs for the first time on television in New Zealand - would be so big and she has started being recognised while out and about.
"I grew up in a small town separated from any kind of industry stuff - I had no idea about the extent of all of the press and the hype and the public profile.
"In the States it's another level entirely."
As well as Teen Beach Movie, Mitchell also stars in The Fosters, a drama that airs on ABC Family in the US about a lesbian couple raising biological, fostered and adopted children.
Produced by Jennifer Lopez, the show has been controversial for it's depiction of "raw" family life, but it has also been received well by critcs.
Complex.com called it "the most important show no one is talking about right now".
Mitchell, who plays a 16-year-old foster child, said it was fun balancing the two completely different roles.
"Teen Beach Movie was definitely challenging because I was singing and dancing and surfing, and The Fosters is challenging in a completely different way.
"It's a much meatier role. The themes are much more hard hitting and it's quite gritty and raw," she said.
"It's really fun for me to be able to do both."
* Teen Beach Movie screens on Sky TV's Disney channel on August 9 at 7pm.