We've only just heard the intriguing news that singer Rita Ora has signed up to play Christian Grey's sister in the upcoming 50 Shades flick and now we know who's to play his mother; it's Marcia Gay Harden.

Deadline Hollywood report that the Oscar winning actress (yes, a winner of the highly prestigious award is joining this would-be-B-list-movie-if-it-wasn't-for-the-hype) has signed up to become Dr. Grace Treveylan Grey.

Alongside Rita Ora she'll join Jamie Dornan as members of the Grey clan and Dakota Johnson who is set to portray Anastasia Steele.

The Pollock actress is currently starring in American sitcom Trophy Wife and has received a heap of award nominations for her diverse acting roles.