Revenge of the Misfits by Jamie Littler

Juniper Bell is on her own. She's betrayed her friends, been double-crossed by the Arcanists, and exiled from her home. The Arcanists have won, and now she can only watch from afar as her city is destroyed, and her twin sister is corrupted by evil magic. But Juni's got one thing going for her - she's a breaker of rules, a maker of trouble. So she'll be back. But can she save the city and everyone she loves, before it's too late?