Nightwish by Sydney Bristow

Serena Sykes was still trying to figure out her place in the world when she discovered the existence of magic. Now armed with limited magical powers, she’ll have to stop her newly discovered family from destroying the world.

With only 48 hours before they fill the world with monsters, Serena will have to rely on a vampire who is as much friend as foe, while trusting in the wisdom of her dementia-ridden grandmother.

No one said saving the world would be easy!