Woman in Black — Eileen Goudge

A housekeeper's daughter and a daughter of privilege find their fortunes reversed in this novel by the New York Timesâ€"bestselling author of The Diary.

The caretaker's cottage is the only home fifteen-year-old Abigail Armstrong has ever known. She and her mother, Rosalie, work for the well-to-do Meriwhethers. Lila Meriwhether is Abigail's best friend, and Abigail has fallen in love with Lila's twin brother, Vaughn. But one day the unthinkable happens: The employers who'd always treated them like family accuse Rosalie of stealing a diamond necklace and banish her and Abigail. A quarter of a century will pass before Abigail sees Lila or Vaughn again.
 
Twenty-five years later, Lila is leading a charmed life as the Park Avenue wife of a powerful businessman. But a scandal leaves her and her son nearly bankrupt. Abigail, the owner of a celebrated homemaking empire, is meanwhile coping with the fallout from a fire in her Mexico factory. In a capricious twist of fate, Lila is forced to take a job as Abigail's housekeeper. But it is Vaughn, now a documentary filmmaker, who will shake up Abigail's world and force her to confront the girl she used to be.