Then She Was Gone by Lisa Jewell

A mother finds her missing daughter’s face in a stranger’s child, reigniting a fifteen-year-old mystery that was never truly buried.

Ellie Mack was fifteen and perfect when she vanished, leaving her mother, Laurel, to spend the next ten years frozen in the aftermath. Just as Laurel begins to move on with a man named Floyd, she meets his nine-year-old daughter, Poppy. The sight of the girl is a shock: Poppy is the uncanny image of what Ellie looked like as a child. As Laurel is drawn into Floyd’s life, her grief turns into a desperate investigation into the resemblance—and the secrets Floyd is keeping. Then She Was Gone is a dark psychological mystery about the weight of loss and the search for a truth that was never meant to be found.