Where Shadows Rest by Mary Ann Weir

Lunar witch Serafina Cimmerian never dreamed her life could be anything other than misery and pain. Enter three dhampirs who would burn the world down with a single word from their beloved. Seri and her husbands couldn’t be happier at Evermere, but her stepmother isn’t about to let her claim a future full of love and laughter. Enter Amabel and Eluned, twin menaces who each have their own ideas about how to show Seri where she truly belongs: On her belly at their feet. Too bad they don’t know the Cimmerians aren’t only monster hunters: They’re monsters themselves. Now Arabesque’s daughters are about to find out what happens when you go walking into the monsters’ den looking for trouble.