But the best-selling author has now discovered that her family had been mistaken about the true identity of her great-grandfather.
Rowling, 46, has recorded a television program with the BBC that shows her coming to terms with the revelation that her family had confused Louis Volant, a war hero awarded with the Legion d'honneur for his bravery during the Battle of Verdun, with her real great-grandfather, who had the same name and also fought for France.
Rowling told the BBC magazine published Tuesday Radio Times that the experience was an upsetting and emotional one. She said taking part in her genealogy research made her so emotional that she cried several times.
"There were a lot of big surprises, some wonderful, and one rather upsetting," she said in an interview.
"However, I went into the program wanting the truth, no matter what it was, because I knew so little about my French ancestry, and I don't regret a moment of it. I loved the whole experience," she added.
When Rowling was awarded the Legion d'honneur for her services to literature in 2009, she described her pride being the second winner of the honor in the family, and how her accomplishments could not compare to the bravery of her ancestor and men like him.
She said that she has undertook the project because her mother Anne Volant, who died in 1990, was very interested in her French roots but never got the chance to explore them.
"A huge motivation in looking into my family history is my mother. It's very much bound up in that loss," she said.
The BBC show, called "Who Do You Think You Are?" will be broadcast later this month.