NEW YORK – Barbara Park, a former class clown who channeled her irreverence into the million-selling mishaps of grade-schooler Junie B. Jones, died Friday after a long battle with ovarian cancer. She was 66.

She was a longtime resident of Scottsdale, Ariz., where she lived with her husband, Richard, and raised two sons.

Starting in 1992, Park wrote more than 30 illustrated chapter books about the smart-mouthed girl with an ungrammatical opinion of everybody — her parents, her teachers, her friends and her classmate and enemy for life, May, who is so mean she won't even acknowledge Junie's middle initial (which stands for Beatrice: "Only I don't like Beatrice. I just like B and that's all," Junie warned).

The books' titles alone were windows into Junie's slangy mind: "Junie B. Jones and Her Big Fat Mouth," "Junie B. Jones and the Stupid Smelly Bus," "Junie B. Jones and That Meanie Jim's Birthday." Junie was stuck in kindergarten for years before Park advanced her to the next class, starting with Book 18 and "Junie B., First Grader (at last!)."

"I don't have a problem being 6 years old in my head," Park once explained. "It's almost embarrassing; if I'm talking to librarians or teachers who know my books and they say, 'How do you do this?' It's not a stretch.

"I find that when I'm struggling to think of how a 6-year-old would feel about something, I just … find the simplest way that you can look at an object or a problem, and not muck it up with all of the stuff that adults do and over-analyze," she said.

Park's books sold more than 55 million copies in North America alone, according to Random House, and the series was adapted into a popular musical theater production.

Parents and educators occasionally objected to the Jones character's personalized language and cheeky ways, worrying that she was a bad influence on her fans. The series has appeared on the American Library Association's list of "challenged" books.

Born Barbara Tidswell in Mount Holly, N.J., Park remembered herself as a troublemaker who knew well the path to the principal's office. She had planned to become a teacher, but a year of being a student teacher for seventh-graders convinced her that her future classroom experiences should be confined to paper. She never bothered writing a book for adults.