Actress Saoirse Ronan will always be thankful for her role in hit new movie Brooklyn, because the film served as her "guardian angel".

The actress plays Irish immigrant Eilis Lacey, who moves in New York in the 1950s and feels herself torn between the Emerald Isle and Big Apple, in the film, and not only does the project mark the first role she has played that is true to her own heritage, but it's also the first time audiences have seen former child star Saoirse as a grown-up.

"It's interesting because even when I was a kid, I never was involved in children’s films apart from maybe one or two," she explained to The Stanford Daily. "They were always quite grown up, and so when I got to the age of about 18 and 19, I was really ready to play someone older, and certainly by the time I reached 20.

"When Brooklyn came along, it was perfect, and it was like a b**ody guardian angel or something coming down and kind of going, 'OK, you’re ready now'. I think just going through that experience, I felt quite changed afterward, but I was very much ready to take that step."

Not that her child star roles didn't gain attention - she was nominated for an Oscar at the age of 13 for her performance in Atonement, opposite Keira Knightley and James McAvoy, and she also won acclaim for roles in The Lovely Bones, Hanna and City of Ember. Meanwhile, experts expect her to pick up another Academy Awards nod for her latest performance.

Despite the fact it was her first leading grown-up role, 21-year-old Saoirse wasn't fazed by the intimate scenes required of her and her Brooklyn co-star Emory Cohen.

"I've never found sex scenes awkward," she previously told People magazine. "With kissing, you can do whatever, but sex scenes have to be choreographed, like, 'What do I do with my hands? Do I take his shirt off?' It's very technical."