Golden Girl by Elin Hilderbrand

When bestselling novelist Vivi Howe dies in a hit-and-run accident, she is given the summer to watch over her family from above and use three nudges to "influence outcomes...down below" by Martha, the person assigned to her from the Beyond. However, Vivi's family needs her now more than ever, so how will she choose when to nudge? Her oldest daughter, Willa, is happily married to childhood sweetheart, Rip, but worries about carrying a baby to term, since she's had three miscarriages. Meanwhile, Vivi's other daughter, Carson, is having an affair with a married man and is in a downwards spiral, using pills, drugs and alcohol to get through the day. Her youngest, son, Leo, has just graduated from high school and is trying to extricate himself from his needy girlfriend, Marissa. Golden Girl explores the lives of those Vivi has left behind-Willa, Carson, Leo, Vivi's ex-husband JP, and best friend, Savannah, in addition to recounting Vivi's childhood and life on Nantucket.