The 'Poison' singer had a small part in the blockbuster movie earlier this year, appearing as main character Christian Grey's character Mia.
Mia appears only briefly in the first book but has a larger role in its sequels Fifty Shades Darker and Fifty Shades Freed, which will both be adapted for the screen.
Appearing on ITV's Lorraine, she said: "I'm a massive fan of the books. My character, Mia Grey, very much evolves in two and three slowly but surely so if they do ask me, of course I will be there!"
Rita's been dabbling in Hollywood plenty these days. She'll be seen playing a drug addict opposite Jake Gyllenhaal in the upcoming Southpaw.
"How I look will probably shock people," she admitted.
She said of her recent experience in Hollywood: "I just sit back and learn. I'm like a sponge just absorbing."
As well as promoting her new single 'Poison' and new album, and filming Hollywood movies, she'll have to find time to fit in X Factor! She's signed up to be a judge on the new series, which starts on ITV later this year.
X Factor's most shocking moments: