The Wicked Divine: The Phoenix

Fi has magic powers! Well, she can summon and control fire, so everyone thinks she's the reason her parents died a horrible burning death. Now an orphan and ostracized ward of the Catholic Church, she must survive the hell that is a Catholic boarding school and the constant isolation of her peers thinking she's a freak and a murder. Until the Pope himself gives her a job, but why does he want her to kill someone?