The Iron Phoenix — Rebecca Harwell

Seventeen-year-old Nadya Gabori lives a life of secrets in the island city of Storm's Quarry. By day, she is the dutiful Nomori daughter, but by night, she sprints across rooftops, testing her abilities of speed and strength, abilities no normal girl should have. And she keeps her growing feelings for her friend Kesali from her conservative family. If her secrets were discovered by her people, the price would be banishment.

But when a murderer strikes again and again while a prophesied storm bears down
on the city, Nadya disguises herself and uses her gifts to fight the chaos that
threatens her home. When Kesali's life is put in peril by the madness, Nadya will do anything to save her, even if it means risking all and revealing she is the one the city calls the Iron Phoenix.