Time Heals — Dina James

Rebecca MacDonnell is strange. More than that, she's a Stranger, a human born with the ability to use her own life's force to heal ethereal beings. Vampires, werewolves, demons, ghosts, goblins, and other things thought only imaginary all need help sometime, and when they do, they come to her. Some things, however, are beyond help. Something is stalking all Ethereals, great and small. Beings of every race are fleeing a terror no one will acknowledge, let alone name. At seventeen, Mistress Healer Rebecca is still learning to manage her power. She must learn to control it before it controls her. Unless it's already too late. When her burgeoning ability gets away from her, that which heals turns to harm and drives her loyal man-wolf bodyguard Billy straight into the arms of the unknown horror. Unlikely new friends are her only hope to finding out what's happened, and she must enter new--and dangerous--territory in order to do it.