As Wikipedia points out, "Who Do You Think You Are? is a British genealogy documentary series that has aired on the BBC since 2004. In each episode, a celebrity goes on a journey to trace his or her family tree."
The episode on JK Rowling belongs to the 8th season (2011), and we can see JK Rowling setting out to investigate her French roots. Jo has always been intrigued by her late mother's French ancestry, but knows very little about it. Beginning her journey in Edinburgh, Jo's search takes her from The Savoy in London, to once-bloody battlefields and the back streets of urban Paris.
You can read the transcript for the first ten minutes of the programme here.