The Flour Sack Duchess by Carolyn Faulkner

A poor American schoolteacher and a wealthy English duke who can never be together are falling hard, fast.

Wynne is visiting her friend, Ivy, in England for the summer. As a poverty-stricken American schoolteacher, she has had to scrimp and save to make the trip. When she meets the formidable older brother of Ivy, he is everything his sister said he was, and more. Bruce is a duke, and thus, he is out of her league. Still, she can't help falling for the handsome but stern aristocrat, even when she knows it will lead nowhere.

The duke can't imagine why he is attracted to his sister's American friend. She is not of their social class, an outspoken American, and in need of correction. But there is something about her he can't resist, even though he knows they can never truly be together.