Faerie Stolen by Anna Applegate

Life with Fae Royalty is proving to be a royal pain in the…
Capturing a Seelie spy should have put Coraline Fray in the Unseelie Queen’s favor. After all, she did singlehandedly save her, her husband, and the stunningly handsome Prince Noah. But instead, all it did was make things between Cora and the royals even more complicated.
To keep the her away from the prince, Cora is reprioritized to be a ladies maid to none other than Noah’s betrothed, but Cora soon discovers this beautiful fae duchess is a snake, twisting everyone around her venomous fingers, including Prince Noah. Her desire to claim the throne goes beyond her arranged marriage, and Cora is the only one who can stop her. But will anyone believe her?
With a war brewing between the kingdoms, things begin to unravel fast…and Cora is stuck right in the middle of it all. Her loyalty has been proven to the Unseelie Court, but will that be enough?