Suitable for Marriage by Ruth Ann Nordin
Erin Larson has a problem that's been following her since she was a child: Alex Matthews. For a reason she can't explain, Alex has convinced himself that they will end up getting married. But she'd rather go through town in nothing but her chemise and petticoats before that happens.
With her two older sisters married, it's her turn to find a husband. As long as Alex is lingering around, she's not going to find the man of her dreams. What she needs is to find another young lady for Alex to turn his attention to. Then, and only then, will she be free.
Alex goes along with this little matchmaking scheme, knowing full well that if he plays his cards right, he'll finally succeed in convincing Erin that they're a perfect match.