The WishKeeper by Maximilian Timm
When a broken-winged, rebellious teenage fairy discovers that her family's WishMakers made an all-important True Love Wish, she secretly ventures to the human world in order to grant it despite the impossibility and to prove that she can be a WishKeeper. An adventure to prove her worth turns into a battle against dark forces determined to harness the wish's power, as well as the insecurities that arise within the little fairy herself.
Shea Evenstar must overcome her doubts, fears and apprehensions, but even more so, the painful discovery of a hidden family secret.
We, WishMakers, all have a WishKeeper assigned to us that protects and guides our wishes toward fulfillment. Teenage, broken-winged Shea is determined to become one.