The 14-year-old star rose to fame after taking on the role of Lyra Belacqua in a movie adaptation of Philip Pullman's bestselling novel The Golden Compass in 2007.
Richards is currently promoting her lead part in another fantasy film, The Secret of Moonacre, which is based on Elizabeth Goudge's children's story The Little White Horse.
"I flicked through the script, read the scene I had to learn, auditioned and got the part in the same day," Richards explained in an interview with the Liverpool Daily Post.
"These films both had strong female main characters," she continued. "I like fantasy, but I don't think that there are a lot of strong female characters around."
The Secret of Moonacre is released in cinemas in the UK on February 6.