Besieged By the Moon by MJ Compton

Fated Mates.
Although werewolf EMT Parker Rowe is anxious to return home to begin his paramedic training, he stops to rescue a she-wolf from a mob. Turns out she isn’t just any she-wolf.
Phoebe McKinn was eight years old when she witnessed the most powerful man in Washington, D.C., slaughter her pack and family. For fifteen years she’s been preparing to avenge their deaths. While tracking her enemy she meets her fated mate and a branch of her pack she never knew existed.
Too bad exacting her revenge will probably get her killed . . . unless Parker can convince her surviving is the best revenge.