DAKOTA FANNING has signed up to play Britains Princess Margaret as a teenager in upcoming film 'Girls Night Out. Dakota Fanning will play Britains Princess Margaret in an upcoming film. The 16-year-old actress will star as the young princess in 'Girls Night Out which tells the story of Margaret and her older sister Elizabeth, who are allowed out of Buckingham Palace for one night to celebrate the end of World War II in Europe. Directed by Michael Hoffman, the movie will be based on true events as chronicled by writer Trevor De Silva. CM