Of Lithuanian Jewish descent, Reims's first came to France in 1933. Her father was Judelas Remzas. Reims's father and aunt escaped the terror of the Vel' d'Hiv Roundup of Jews in Paris in 1942, but were separated in the confusion of war. Alone in Vichy, Reims joined the Jewish resistance group, Organisation Juive de Combat. She, her father, and aunt were reunited in 1944 but her uncle, Gustav Gumpert, was murdered at Auschwitz.