Storm Siren Trilogy by Mary Weber
Seventeen-year-old slave girl, Nym, should not exist. In a world where Elementals are only born male, and always killed at birth, she is an anomaly at best. At worst, people around her die. When a court emissary identifies her weather-manipulating ability as a weapon, Nym is purchased and put to work honing her skills. With time running out for the kingdom of Faelen, Nym might be all that stands between it and the technologically-advanced horror racing down upon them; not to mention the rumored reemergence of the monstrous shapeshifter, Draewulf. But some elements even she can’t control. Nym must decide whom to trust as she’s unleashed into a world of assassins and political betrayal surrounding a young king fighting for his throne, a tired nation that has forgotten its calling, and her handsome tutor whose dark secrets could destroy both her people and her heart.
1) Storm Siren
2) Siren’s Fury
3) Siren’s Song