The Bonemender Series by Holly Bennett

Gabrielle is the princess of DesChenes. She is also a bonemender with special abilities so when she learns of the war that's threatening her borders she sets out to help her father and brother on the front. She knows that she must be present on the battlefield, but she never could have guessed why.

The war is over, but the danger is not.In "The Bonemender" Gabrielle acepted her talent. Now, the war is over and both Gabrielle and her brother Tristan struggle to deal with the consequences. They have yet to understand that the threat from across the mountains has only withdrawn and they will have to fight for their lives and those of the ones they love, as another threat arises closer to home.

A kidnapping and a deadly plague.