Cold Blood — Donna Ansari

As the winter holiday season descends on New York City, vampire Emma Hammond is anticipating celebrating with Tammy and David, her witch and werewolf roommates. But when an odd Christmas ornament unleashes waves of the undead from her neighborhood graveyard, Emma finds herself as an unwilling shield between ravenous zombies and an unsuspecting city. Even worse, despite having everyday dealing with supernatural creatures, Emma finds that she has an unnatural aversion to the shambling dead, and must get to their source and stop the invasion before she's forced to cancel her holiday party!