Barbara Park said she wasn’t grown-up enough to write grown-up books, but she certainly made a lot of children happy. The author of the beloved Junie B. Jones series died after a long battle with ovarian cancer, her family confirmed on Sunday. She was 66. Park wrote more than 30 illustrated books about Junie B. Jones, kindergartener and first-grader, since 1992. The books went on to sell millions of copies—as well as draw ire for Junie’s bad grammar and mischievous ways (in fact, it is one of the top 100 banned books). Park said she herself was a troublemaker who often was in the principal’s office, and she said she was inspired by Judy Blume to write for children. Park is survived by her husband, Richard, and their two sons.