Chasing the White Witch — Marina Cohen

When Clair discovers a book of spells, she quickly learns that she can't solve her problems with magic.

Teased by her older brother, bullied by the popular girls at school, and plagued by a blistering pimple that has surfaced on the tip of her nose, twelve-year-old Claire Murphy wishes she could shrivel up and die or spontaneously combust. But when a mysterious book appears at her feet in the checkout aisle of a grocery store, Claire is confident all her troubles are over. Following the instructions carefully, Claire dives nose-first into reeking remedies, rollicking rituals, and silly spells. It's only when she recklessly disregards the Law of Three that the line between good and evil blurs and Claire must race against time to undo all of the trouble she's caused.