The White Lady by Jacqueline Winspear

In 1947, Elinor White's quiet life in the village of Shacklehurst is disturbed when she sees a local family, The Mackies, being threatened. Elinor feels particularly protective of Susie--Jim and Rose Mackie's young daughter. It turns out that Jim, has broken off ties with his family, who are involved in organized crime in London. They have come to Shacklehurst to try and convince Jim to join them on a job. He refuses. Elinor then takes it upon herself get the crime family to leave Jim, Rose, and Susie alone. Elinor grew up in Belgium during World War I, and was involved in work for the Allies in both world wars, so she has the connections and skills to make it happen. The story of Elinor's childhood and time before arriving in Shacklehurst alternates with that of the Mackies and Elinor. One of Winspear's best.