Jinnie Wishmaker

Eleven-year-old Jinnie has a dilemma--she can grant wishes, but she can't control the results. 

When her magic is discovered, her school counselor tells Jinnie to join a group of fellow students with similar power problems. Maddy's touch makes people explode in anger. Grace can instantly turn anyone into a best friend. 

But their loose use of magic attracts the attention of the Loki, a group of magic thieves and pranksters. They want to steal an open-ended wish from Jinnie, and it will take all the limited and messed-up magic that she and her friends possess to make sure their powers don't fall into the Loki's greedy hands. 

Jinnie Wishmaker is the first book of the Magic Mayhem series for 9-12 year olds. It is a standalone story. The series continues with Marcus Mender.