Slay by Laurell K. Hamilton

Laurell K. Hamilton has captivated readers with her gritty, seductive tales of vampire hunter Anita Blake for thirty bloody fantastic years. Now, in the thirtieth novel in the #1 bestselling series, wedding bells are ringing. But before Anita can make it to the altar, she must face an obstacle more daunting than any supernatural threat….

Necromancer Anita Blake is small, dark, and dangerous. Her turf is the city of St. Louis. Her job: U.S. Marshal—Preternatural Branch. She’s faced horrifying monsters and brutal killers and come out the other side still standing.
Considering how things in her life tend to go, Anita never expected her walk down the aisle with Jean-Claude to go smoothly. They’ve already been confronted with naysayers and a power-hungry ancient evil, but now Anita has to do the one thing that actually scares her: introduce her very religious, very human relatives to her fiancé—the newly crowned vampire king of America.
As Anita tries to keep the peace between the family she left behind and the family she’s chosen, dark forces jump at the chance to take advantage of the chaos. With her happy-ever-after at risk and everyone’s immortal souls hanging in the balance, Anita grapples with a hard truth: Blood makes you related, but loyalty makes you family.