Kim Harrison's Hollows series. The main characters are Rachel, a witch/bounty hunter, and Ivy, a vampire, who both live and work together. Not canon f/f, but very shipable. Ivy also a younger sister, Erica, who she is very protective of. If you're wearing your incest goggles it is also very shipable.

The series premise is basically what if the Thanos snap happened (but with tomatoes) but only affected humans and now the magical population size is equal to humans for the first time and can live openly.