Promised in Blood- Sadie Kincaid

Broken Bloodlines 2 (after forged in blood) 

An ancient prophecy. A betrayal so deep it will echo through eternity.

Ophelia Hart is no ordinary elementai. In fact, she is extraordinary in every single way there is.

And now that she knows her true heritage and has bonded to the most powerful vampire who ever lived, and the three ruthless vampires he sired, she wonders if she might finally know some true happiness. It seems at last within her reach-so long as the truth of her identity remains a closely guarded secret.

But secrets can't remain so forever. Ophelia must learn to harness the magical abilities she's awakened before the rest of the world discovers who she really is. And although her four bonded mates will do all in their power to protect her, there are forces at work that even they cannot fathom.

Destiny beckons, but betrayal lurks just around the corner. And debts will be settled for oaths that are PROMISED IN BLOOD.