A tuckered-out mother requests a role reversal in this playful rhyming picture book. Regaling a young child with her day-s tasks (-She worked all day at the computer store./ Came home to a big mess on the floor!-), the bespectacled, brown-skinned mom sweetly requests that her daughter -Read me a story and pat my tummy?/ Wipe my nose when it gets runny?- In Clark-s repeating exhortation: -Mommy-s too tired to be Mommy tonight.- Her daughter gamely attempts to facilitate a nighttime routine but, in classic fashion, soon finds herself getting tired, too. Vibrant digital illustrations by Persico portray a comfortable home for the duo-s gentle game. Though Mommy-s plight is easy to emphathize with, there-s no hint of resentment: this mama may be exhausted, but she loves her kid all the same. Ages 2-6. (Mar.)