The Loner's Bride (Wyoming #4)
Ruth Ann Nordin

Then one day, a thought comes to her out of nowhere: if only they were more like Jeremiah Barlow who happens to be running the orphanage. And suddenly, she’s looking at the man who’s been a friend of her family in a whole new light. He’s perfect. Mature, kind, and gentle. Best of all, she’s attracted to him in a way she’s never been attracted to anyone before.
It’s not long before Jeremiah becomes aware of Katie’s interest in him. And worse, he’s just as interested in her. But it would never work. He’s twice her age. His best days are behind him.
Katie, however, is not one to give up. When she wants something badly enough, she’ll move heaven and earth to get it. And Jeremiah is on her list.