The Witch Queen's mate by Jennifer Karter

There couldn’t have been a worse time for Barra to be chosen by her gods as the next queen of the Neamairtese. She and a group of her people are being marched to the distant Empire of Victricus to be slaves. Headstrong and independent, Barra never saw herself as a leader, and her chances of saving her people dwindle when her heart’s mate turns out to be a Svekard, the ancient sworn enemy of the Neamairtese. Without her mate, Barra cannot complete her connection to divine magic and free her people. Silvi, a Svekard veterinarian, was simply trying to survive the march south when she was kissed by the Neamairtese witch, Barra. Now, Silvi has inhuman speed and strength to protect the witch, even at the cost of hurting her own people, an incredible dishonor. Can Barra and Silvi’s love overcome their ingrained hatred and prejudice to bring their people together and save them all not just from slavery, but destruction?