This past December, Lily James was lying on a beach in Jamaica, recuperating. It was the only sane way to end a year during which the actress shot a season of Downton Abbey and three films, including Cinderella, in which she plays the title role opposite Cate Blanchett’s evil stepmother, out March 13. “I can finally talk to you like a human being,” she said over the phone. “Before I got here, I felt like a weird, twisted version of myself.”

In conversation, James comes off as a combination of Lady Rose MacClare, the impulsive mischief-maker at Downton, and her earnest, straight-arrow Disney character. “As a child, I loved fairy tales and princesses,” James, 25, recalled. “But a lot of people think they’re not great role models for kids: aspiring toward just marriage or a man…” She trailed off, realizing she was quite possibly biting the hand that just gave her career a huge boost. “But I feel like in the film we try to focus on a message of strength and kindness as a way to live your life.”

Growing up in Surrey, England, James sang and performed, but she never went the Shakespeare and Jane Austen route—that is, until she arrived at drama school when she was 18. “My head exploded. I became a massive geek.” Like many British actresses, she’s wary of being typecast in period dramas, but a corseted Tiffany-blue gown was unavoidable for Cinderella’s grand entrance at the ball. “It was so tight, I could only eat soup,” she said, laughing. “I basically spent most of that scene burping.”