Sixth-grader Nadia, whose widowed mother has convinced her that she has a congenitally ""bad heart,"" chafes under the ""poor sick girl"" label. Friendless at school, she's intent on gaining the validation that a lead part in the upcoming class play would provide. Secretly, she practices all the roles with her paper dolls. Nadia believes that her audition for the lead role was best, and is devastated when Mrs. Riley, who had called her ""an amazing little actress,"" awards all the parts to other children. Bit by imperious bit, Nadia (slated for home-schooling come January) counters her controlling mother's manipulations, even wrangling a secret visit to a classmate's house. A frightening car accident and Nadia's surreptitious look at her chart in Doc Smith's office intensify the unraveling of Mama's skein of lies. Nadia's redemptive realizations-from her new understanding of her mother's mental illness to her shrewd assessment of her conniving classmates-feel genuine. A few characters, such as also-ostracized Carmalee, stand out, and Arrington (Camp of the Angel) nicely sketches the classroom pecking order. But while the subject of a parent's pathological overprotection (unusual for a middle-grade novel) compels the third-person narrative, Nadia's whiny self-absorption might well prevent an empathic response from readers. Ages 8-up.