Imprison the Sky (The Elementae, Bk. 2) by Gaughen, A. C.

Stolen from her family as a child, Aspasia has clawed her way up the ranks of Cyrus's black market empire to captain her own trading vessel--and she risks it all every time she uses her powerful magic to free as many women, children, and Elementae from slavery as she can.

But Cyrus is close to uncovering her secrets--not only that Aspasia is a wind Elementa with the ability to sail her ship through the sky, but that she is also searching for her lost family. And if Aspasia can't find her younger siblings before Cyrus does, she will never be able to break free.

Armed with her loyal crew full of Elementae and a new recruit who controls an intriguing power, Aspasia finds herself in the center of a brewing war that spans every inch of the ocean, and her power alone may not be enough to save her friends, family, and freedom.