Back to the Bayou by Brooke St. James

Family Series, but it can be read as a standalone.

Amelia Martin was the youngest of three girls. Both of her older sisters had already found their soul mates, and Amelia felt like she was well on her way to that with Hank Marksberry.
Hank seemed to have everything she was looking for. He was handsome, intelligent, and would undoubtedly have a successful career. Amelia decided to bring him home during Christmas break to meet her family, thinking it would be the beginning of their happily ever after.
The only problem was that Hank could never compare to Caleb Reeves. When Caleb unexpectedly appeared at the airport to offer Amelia and Hank a ride, she was faced with a lifetime of memories and feelings she had managed to avoid since she’d left home.