White Wolf by Suzanne Roslyn

Moving onto a the shifter reservation near the Shadow Lands of the Evergreen Mountains, Audrey Johnson risks losing guardianship of her young shifter nephew, Toby. A human without any connection to the mountain, Audrey must find a mate or hand over custody to wolf shifter, Liam Holden, and leave the shifter reservation and her nephew forever.
Desperate and lonely all these years, Liam isn’t sure he can trust his wolf spirit’s instincts when it comes to finding his one true mate. Audrey tries to lure Liam into mating with her. As the mate bond grows stronger between them, and Audrey is running out of time to find a mate. Liam is forced to protect her. His wolf and his heart will have to claim Audrey before the dark shadows of the mountains take her from him.