Moon River (Vampire for Hire)

Seven years ago federal agent Samantha Moon was the perfect wife and mother, your typical soccer mom with the minivan and suburban home. Then the unthinkable happens, an attack that changes her life forever. And forever is a very long time for a vampire.
Now in Moon River, private investigator Samantha Moon is asked to look into a string of bizarre murders, murders that are looking more and more like the handiwork of a bloodthirsty vampire. But when her sister, Mary Lou, goes missing, Samantha, Allison, and Kingsley take the fight underground...into the dark heart of a vampire's lair.