( EW.com ) -- Rita Ora , best known as a singer signed to Jay Z 's Roc Nation label , has been cast as Mia , Christian Grey 's adopted sister , in `` Fifty Shades of Grey . '' The British pop star has only four IMDb credits to her name , so this will be a pretty high-profile introduction to her acting . Dakota Johnson on 'Fifty Shades ' : I really understand it . Ora confirmed the news , first reported by The Hollywood Reporter , on Twitter : . `` Fifty Shades of Grey , '' which just began shooting Monday and arrives in theaters in February 2015 , stars Dakota Johnson and Jamie Dornan as Anastasia Steele and Christian Grey . See photo of Dakota Johnson and Jamie Dornan on set . The best-selling book-turned-potential film franchise also stars Max Martini ( bodyguard Jason Taylor ) and newcomer Eloise Mumford ( roommate Kate Kavanaugh ) . In the books , Mia is described as tall and curvaceous ( Ora has that covered ) , but she 's also said to have raven hair . Does Ora fit the bill in your mind ? See the original story on EW.com . CLICK HERE to Try 2 RISK FREE issues of Entertainment Weekly . © 2011 Entertainment Weekly and Time Inc. All rights reserved .
Rita Ora has been cast as Christian Grey 's wife in ` ` Fifty . '' The Brit pop star is a relative newcomer to acting . Ora broke the news on Twitter .