Josie’s real name is Jocelyn. She has Coeliac Sprue, which is now known as celiac disease. For those with this autoimmune disease, eating foods that contain gluten causes damage to the small intestine and inhibits the body’s ability to absorb nutrients. Because supplies are scarce during wartime, Josie must learn to trade for foods on the black market. Her experiences with chronic illness make her very resilient.

Josie’s parents separated after an acrimonious marriage. Josie’s mother, Drusilla, was a doctor and moved Josie to France because the hospitals were more welcoming to female doctors. As a teenager, Josie learned that her mother’s friend “Aunt Quinn” was actually her lover. Josie’s father blackmailed her mother because of her sexuality and threatened to expose her relationship with Quinn to the hospital if she asked for anything from him.

When Josie lands in France during the primary portions of the novel’s 1940s timeline, she is ecstatic to learn that her partner is Noah, with whom she strongly bonded during the intense experience of their first operation. Her code name for this operation is Chloe. She is a bit apprehensive about working as a nanny since she does not have much experience with children.