Julie Berry, the author of "The Scandalous Sisterhood of Prickwillow Place, " has never solved a murder or attended boarding school. Her manners are decidedly improper. But she is part of a scandalous sisterhood. She's the youngest of seven children, six of whom are girls, and if they'd ever had a chance to conceal a corpse and run a school, they'd have jumped on it. Today she lives in eastern Massachusetts with her husband and their four sons and two cats.