Beast of Dracula (Princess Dracula Book 4);

Socialite. Flapper. Vampire. Beast.
Ruxandra once stalked the woods of Europe as a blood-hungry Beast. Now, eternally eighteen, she’s determined to forget all that, to dance, drink and love her way through Jazz Age New York. 
Elizabeth Bathory is the only human Ruxandra ever turned - the second of only four vampires in the world. She’s also a psychopath. And when she knocks on Ruxandra’s door, Ruxandra’s carefully constructed world begins to fall apart. 
Soon Ruxandra is forced to leave her carefree life among humans she loves for the hot streets of Los Angeles, where stars dance in the Cocoanut Club and a vampire isn’t the only thing prowling the night. 
With each new clue comes new questions, and with each new encounter, Ruxandra comes closer to unleashing the terrible Beast that lives inside her.