On Mystic Lake by Kristin Hannah

Annie Colewater's life fell apart the day her eighteen-year-old daughter left home and her husband of twenty years abandoned her for a younger woman. Shattered, she returns home to the small Washington town of Mystic, seeking solace to the haunting emptiness of her own soul. Here, a broken woman will open her heart to a shattered little girl and her father, Nick Delacroix, an embittered, grieving widower. These three lost hearts find the courage to trust in love again--never expecting the turn of events that will force Annie to make a harrowing choice between what is...and what could be.