His Convenient Wife by Ruth Ann Nordin
Harriett Larson has been in love with Stan Craftsman for years, but he’s never paid any attention to her. Instead, his focus has always been on her twin sister. So when Stan proposes to Harriett, she knows it’s only because he needs a mother for the little girl he recently adopted.
And while her first reaction is to turn him down, she can’t bring herself to turn her back on an innocent child who needs her. So it is with reluctance she agrees to marry him. But only on one condition. Theirs will never be anything more than a marriage of convenience. She will not be vulnerable to him ever again.
But as soon as Stan marries her, he regrets the deal he made. She’s not the wallflower he thought her to be. In fact, she’s much more appealing than her sister. The problem is, how can he convince her of that so they can turn their marriage of convenience into something much more?