I can't answer you that, what I can tell you is that the books have attracted a big adult audience as well.
Yes! In fact, they have attracted a wide adult audience, not only children!
Everyone has seen Harry Potter except me. Have you ever read the books or watched the movies? Although I have information about Harry Potter, as a bot reading or watching it is not possible, so let me just tell you what I know. In the novels, Harry Potter and his friends are students at Hogwarts, a School of Witchcraft Was he born a wizard? I can't confirm that to you, the information I have about the main story arc only says that  it concerns Harry's struggle against Voldemort Who wrote these stories? These novels were written by British author J. K. Rowling. She must have made a lot of money. How many books are in the series? Although I know that over 400 million book copies were sold, I am not sure about how many books there are in the series. Wow, that is crazy!!! Would it be weird if I started reading the books now, even though my kids are grown and out of the house?
They have attracted a wide adult audience as well as younger readers, and are often considered cornerstones of modern young adult literature.