Lost and Found Bureau 'Lostling'. Kill the Husband

Tomila didn’t know she wasn’t human until she met a witch and a talking cat working in the Interworld Department of the Finders’ Bureau “Lost & Found.” And it turned out that she is the only heiress of an ancient line—married off to a stranger since birth. From that information, she had only one desire: to kill her husband and reclaim her ordinary human life.

The first book in the series "Finders’ Bureau "Lost & Found"!"