Let me fix that for you
(Book)

Twelve-year-old Gladys Burke may not have many friends, but at least she has her empire. From her table at the back of the cafeteria, Glad arranges favors for her classmates in exchange for their friendship. She solves every problem, handles every situation, and saves every butt. But the jobs keep getting harder, and when Glad decides the problem that most needs fixing is her parents' relationship, she finds herself in way over her head. She'll have to call in all her favors and use all her skills to help the person who most needs it-herself. --from Amazon.