Waiting for morning / Margaret Brownley.

Enhanced descriptions from Syndetics:

Molly Hatfield comes to Arizona Territory seeking stability and security. But living in Cactus Patch provides her with more than she ever dreamed of.

There is nothing Molly wouldn't do for her teenaged brother, Donny. Blaming herself for the accident that left him wheel-chair bound, Molly has dedicated her life to his care. But in 1896, gainful employment for a woman is hard to come by. So when Molly learns that an eccentric rancher in Cactus Patch, Arizona, is looking for an heiress--someone to take over management of the ranch in exchange for future ownership--she jumps at the chance to provide a real home for her brother.

If she proves to have a knack for ranching and agrees to remain single for life, the ranch can be hers. Neither stipulation worries Molly. She's resourceful and hardworking. And she gave up dreams of marriage long ago when she dedicated her life to her brother's well-being.

However, Molly didn't bank on meeting Dr. Caleb Fairbanks, the town's handsome and charismatic young doctor. Caleb has a way with Molly that makes her nervous. But it's how he is with her brother that really alarms her. Caleb sees past the wheelchair and genuinely likes Donny, but Molly fears he's putting unrealistic ideas into her brother's head. Falling in love with Caleb would threaten everything she's worked for, even her brother's future happiness.

But it could be the very reason God brought her to Last Chance Ranch.