Known best for her Horrible Harry and Herbie Jones series of children's books, this American writer also worked as a California-based elementary school teacher.
After earning a history degree from the University of California, Berkeley, she entered the teachers' training program at California State University, Hayward.
Her Horrible Harry books became reading instructional fixtures in American elementary classrooms.
A native of Berkeley, California, she later settled in Connecticut with her husband and fellow writer Rufus Kline and her daughters Emily and Jennifer.
She was born in the same year as fellow American children's author Mercer Mayer. Mayer, who penned the Little Critter and Little Monster series, also catered to beginning readers.