Shore Lights - Barbara Bretton
I was expecting this to be a summery book, but the season is winter; right before Christmas. I guess that is snow on the beach on the front cover of the book ;-)

This is the first book in the Shelter Cove series (Book #2 is Chances Are).

This book takes a close look at a mother-daughter relationship, how divorce affects the children in a family, as well as the possibility of the divorced couple still loving one another.
The main characters are Maddy, her Mom-Rose, Hannah-Maddy's daughter, Aidan, his daughter Kelly and a bunch of other cousins and townspeople throughout this book.