Under the Burning Stars by Carrigan Richards

Everyone said it was over. But Ava knew it was just the beginning. After risking everything and beating the odds to be with the love of her life, Peter, life should be good for Ava. Far from it. An altercation with the humans has left him struggling with his new life as an Enchanter, and Ava can feel him slipping away. Nightmares of her mother's murder haunt her, and leave her grappling with the darkness inside herself. She will stop at nothing to uncover the truth about her mother, even if that truth is more dangerous than anything she's faced before. After her search for knowledge lands her on the verge of banishment from her coven, Ava must seek forgiveness from everyone and forge her own destiny as the coven faces an onslaught of war.