Chameleon — Kristine Kathryn Rusch

The kids at school call Wilhelmina “Cry-Baby Witch.” Kinda true. At least about the witch part. But they don't know that, and Willi still struggles to control her magic.

So, when she gets caught using her magic to help one of the animals in Mrs. Anderson's room, Willi fears the worst. Because creepy Craig Maddson now knows Willi's secret. She knows he plans to tell on her. But she has no idea how to stop him.

“Rusch's short fiction is golden.”
-- Kansas City Star