The Rest of the Story by Sarah Dessen

Seventeen-year-old Emma Saylor Payne finds herself spending the summer with her mother's side of the family at North Lake, a place she hasn't visited since childhood. Her mother passed away when Emma was ten, and she has since been raised by her father. At North Lake, Emma reconnects with relatives and learns more about her mother's past, including struggles with addiction. She grapples with her dual identity—Emma to her father and Saylor to her mother's family—and the complexities of her family's history. Through these experiences, Emma embarks on a journey of self-discovery and healing.