In her youth, Brigitte had fallen in love with the American Bobby Davis during summer 1936. That summer, the two had seen I'm No Angel starring Mae West in cinema. After Bobby had left France, they wrote letters to each other each week until the outbreak of World War II.
Brigitte became a member of the French Resistance cell of Sainte Claire during the German occupation, where she was responsible for decoding messages from the Allies. She also apparently had some experience in the use of shotgun as was charged with guarding the resistance base in the other members absence. She also apparently worked in Katrine's restaurant in unknown role as part of her cover as resistance agent. Early on in her work as a resistance agent, a high-ranking German officer became romantically interested in her and she promptly took advantage of his affections so she could gain access to valuable information. The resultant sexual relationship lead to Brigitte becoming pregnant. Most villagers despised her for this, but her pregnancy gave her nearly unlimited access to the German headquarters.