Last year Sean Ferrer filmed a show for BBC called My Best Friend: Audrey Hepburn. It was part of an ongoing series about behind-the-scenes biographies of celebrities as told by their best friends. As Sean himself said at the time, "It doesn’t happen always that your parent is also your best friend," but he and his mum were always very close. He had also called Audrey his best friend in his book An Elegant Spirit. I haven't seen this show yet, but if you care to register at the website of the company that produced this, 3DD, then you may be able to see it for free online! (I'm waiting for my password.) You can click here to learn a bit more about the documentary, and you can register for your password here.
Also, there's been lots of activity in the Audrey Hepburn community. If you haven't already, check it out!