Book about two sisters

This might be an older book. All I can remember is that there were two sisters, once of them seemed to live the charmed life and was more loved by the family, and the other sister was sad and alone (?) and befriended an older man nearby? She may have started to fall for him, and can’t remember. I think there was some conflict because the popular sister either befriended the man too or married him or something? It was a sad book and left me with a lot of questions, read it years and years ago.