While Jo may have millions of fans around the world, she also has her critics. Some have labeled Harry Potter as being too dark and frightening for children. There have been religious critics who have accused the books of promoting witchcraft, and some have even campaigned for the books to be banned from schools. Jo says she wasn't trying to make a religious statement when she wrote the books.
"I'm not pushing any belief system here," she says. "Although there is a lot of Christian imagery in the books. That's undeniable. But that's an allusion to a belief system in which I was raised."
Jo says she can understand why some parents might find Harry Potter too mature for their children. However, she doesn't think that the topics of witches and magic should be avoided altogether. She says these kinds of stories have been told for hundreds of years, and they will continue to appeal to children for hundreds of years to come because people like the idea behind magic.
"I'm not saying I believe magic is real—I don't," she says. "But that's the perennial appeal of magic—the idea that we ourselves have power and we can shape our world."