Black Witch chronicles

Elloren Gardner is the granddaughter of the last prophesied Black Witch, Carnissa Gardner, who drove back the enemy forces and saved the Gardnerian people during the Realm War. But while she is the absolute spitting image of her famous grandmother, Elloren is utterly devoid of power in a society that prizes magical ability above all else. When she is granted the opportunity to pursue her lifelong dream of becoming an apothecary, Elloren joins her...

"Elloren Gardner hides the most powerful secret in all Erthia--she is the Black Witch of Prophecy, and destined to triumph...or be used as the ultimate weapon of destruction. Separated from everyone she loves, isolated and hunted, Elloren must turn to the last person she can trust--her fastmate, Commander Lukas Grey. With the Mage forces of Gardneria poised to conquer all of Erthia, Elloren has no choice but to ally with Lukas and combine their power...