Shadow Walker (Shadow Walker #1) by Jina Bazzar
Nine Houses rule the nation, and Melaina stays away from them at all costs. She lives by one hard rule: never mingle with the supernatural. Driven by fear of discovery, she remains on the fringes of society, occasionally stealing to provide for her aunt and her brother. When the opportunity to work for a corporation not owned by a House falls into her lap, she can’t believe her luck. With a forged non-magical certification in hand, she’s ready to embrace a bright future. Unfortunately, the future is an ambush by blackmailing thugs, notorious assassins, and an unscrupulous House leader. Entrenched in House conflict, Melaina’s dream of normalcy has turned into her worst nightmare. Now, to save her brother and family secrets, she’ll have to partake in one last dangerous heist. Success means exposing her forbidden magic, but failure could cost the lives of everyone she loves.