"I was worried because it's coming into something that's already established like feeling like the new kid at school, but everyone was really lovely and really welcoming and hilarious. It's a really good vibe on set, which I didn't expect," the Australian actress told PEOPLE at The Hollywood Reporter and Jimmy Choo's "The Most Powerful Stylists in Hollywood" Dinner.
"I feel like the first movie did so well, so everyone is more relaxed on this one," she continued. "It's just a really good environment to be in."
Your First Look at the '50 Shades of Grey' Sequel
Heathcote struck it lucky when she was cast to play Christian Grey's – played by Jamie Dornan – ex-girlfriend Leila Williams in the Fifty Shades of Grey sequel, but she says it wasn't hard to keep herself from going all fan-girl on the ultra good looking actor.
"It's so funny because Jamie, himself, is so not that," she laughs. "He's a super laid back Irish man with a great sense of humor, so it's weird to even imagine him as the smoldering thing, but I get it because he's super handsome."
Fifty Shades Darker is set to hit theaters on Feb. 10, 2017.