Though her older sister and brothers tease her relentlessly, Patsy Small is magnanimous: when they have chicken pox, she brings Jim drinks, loans Jane her favorite book, and gives Hugo a toy for his hamster. In return, Patsy gets some grudging approval; even so, when she falls ill, it's back to normal: the recovered sibs refuse loans, are too busy to play, and revert to their habitual insults. Still, when Dad provides the bored convalescent with some enticing art supplies, they're all eager to share. Patsy decrees otherwise; moreover, she constructs a toy village complete with a cemetery in which all three appear: ``Here lies Jane Small, A Mean Sister.'' A quick reformation ensues, and Patsy generously revises her tombstones. Though the sibs' concluding turnabout is easily won, the family dynamics (including Dad's kindlier teasing) are right on target. Wilson, who also illustrated Little's Jess Was the Brave One (1992), provides colorful realistic illustrations that are especially good at conveying the subtleties of the children's feelings. Another solidly entertaining family story from this fine Canadian author. (Picture book/Young reader. 4-8)