She was born on 31 st of July 1965 in England. Now she is 51 years old. In addition, she wrote a big amount of books: Harry Potter, Fantastic Beasts & Where to Find Them, Quidditch Through the Ages and so on. Her ideas about harry potter book were written on the napkin while traveling to London by train.The most famous book is Harry Potter because it was sold to the huge amount of people in over the world.