Lost Rings and Other Things by Raccio

Travel to the underbelly of a magical school with the daughter of a murderer. Sixteen-year-old Emily can make anything she touches disappear-not a bad skill for a thief. In a realm ruled by magic, her ability should grant her an easy life. However, stuck in the Commons along with those unlucky enough to be born without magic, stealing to survive is anything but easy. But when one of the realm's Masters catches her robbing a supply caravan, Emily is given the rare chance to escape-if she agrees to put her magic to more law-abiding use. Desperate and friendless, she moves to Selwyn castle, where dragons, and the best talents of the realm, are trained to rule. Yet Selwyn's holds secrets of its own. Strange attacks and break-ins turn unwanted suspicion onto Emily, throwing her into a race to find the real criminal before she's sent back to the Commons for good. But the closer she gets to the truth, the quicker her past-and the festering hatred for the non-magical community-catches up to her. And with time running out, she'll have to return to some old tricks to make it out of Selwyn's alive.