Reliquary By Hannah F. Whitten

Reliquary is a fantasy romance about Princess Gwen, a young widow who is expected to enter a political marriage with the terrifying Taloned King, ruler of the hawk-shifters. The marriage is intended to broker peace between their kingdoms, but Gwen soon discovers that her new husband and his people are not what she expected.

As an unexpected love develops and Gwen becomes part of a new family, she is forced to confront the forbidden magic within her own lineage. Protecting the people she has come to love may require her to reclaim a power that has been hidden for generations.