Children with their own insightful rules on life have become a popular vehicle for poignant themes. Zoë Lama (think Dalai Lama) is a pint-size seventh-grader with unwritten rules of advice for friends and classmates. After defusing a bully situation on the playground, Zoë Monday Costello gains such respect and clout that her small stature does not prevent her from having an overly inflated view of her opinions. Bestowing her guidance for things like picture-day clothing and boyfriend behavior can be a bit overbearing at times. Written in a first-person know-it-all voice, a larger bold type for pointed emphasis, a smattering of IM language and a sprinkling of pen-and-ink drawings, this deals with typical fare for the fatherless Zoë. A full plate of “responsibilities,” from chairing the school’s dance committee, to mentoring new student Maisie, to keeping Grandma out of assisted living while scheming to have Mom marry the math teacher, all play against the everyday middle-school drama. When plans and guidance backfire, Zoë acquiesces to unwritten rule #10. Just when everyone is weary of Zoë’s self-proclaimed knowledge, Cohen gets to the point and reverses her protagonist’s attitude, concluding with the message, “Sometimes the best way to be a friend is to just let people be themselves.” Sitcom style for familiar themes. (Fiction. 9-12)