Beautiful Day by Elin Hilderbrand

The Carmichael and Graham families are gathering on Nantucket for the wedding of Jenna and Stuart.  Following the events over a summer weekend, the story is told through the eyes of three characters.  Jenna's father, Doug, realizes that he doesn't love his second wife, Pauline, and misses the love he felt for his late wife, Beth, who died of cancer.  Jenna's older sister, Margot, is obsessing over the secret relationship she's having with her father's law partner, Edge.  Stuart's mother, Ann, a state senator from North Carolina is finding it hard to stomach the presence at the festivities of her husband's second wife, Helen, even though she was the one who invited her.  With Hilderbrand's trademark of the interpersonal relationships of the wealthy set against the backdrop of Nantucket, Beautiful Day is an engaging beach read.