The 39-year-old former model, who is currently embroiled in a bitter divorce battle with Sir Paul McCartney, has flown to the US to discuss the film and is convinced the Oscar-winning actress would be perfect for the lead role.
A source said: "She feels someone like Reese Witherspoon should play her. Heather wants an unknown to play Paul.
"Heather sees this film as the tragic and empowering story of her life. A young model who gets run over and loses her leg and marries her prince. But the most interesting part of the tale will be the dark goings on behind closed doors."