Rita Ora with Jamie Dornan (inset)
Splash News Online; Inset: WENN
12/03/2013 at 07:30 PM EST
There's more casting news from the set
of Fifty Shades of Grey
British singer Rita Ora
has been cast as Christian Grey's adopted sister, Mia, in the big screen adaptation
of the steamy bestseller by E.L. James, reports Variety
Ora joins stars Jamie Dornan
and Dakota Johnson
, who play lovers Christian Grey and Anastasia Steele.
Also joining the cast is Oscar winner Marcia Gay Harden, who'll play Grey's adoptive mother, Variety reports
will take on the role of Anastasia's best friend Kate Kavanaugh, Max Martini (cute!) will play Christian's bodyguard
Ora triumphantly shared the casting news on her Twitter
"It's official!" she wrote. "I've been cast in @FiftyShades of Grey as Christian's sister Mia. #FiftyShades"