Hand of the Gods: The Sahra Chronicles Book 2 by Miriam Newman
Young and deeply in love, Sange does not realize when she unquestioningly follows her husband to two different fortresses that the greatest danger will come from another woman.
Barnes and Noble: https://www.barnesandnoble.com/w/book/1144515969
Smashwords: https://www.smashwords.com/books/view/1497018