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 a 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 shotguns, as she was charged with guarding the resistance base in the other members' absence. She also apparently worked in Katrine's cafe as part of her cover as a resistance agent. Early on in her work in the resistance, 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. Brigitte played her role well and exhibited skill in manipulating her German lover, actively playing on his affection for her. Most villagers despised her for her relationship with the German, but her pregnancy gave her nearly unlimited access to the German headquarters. As such, she subsequently used her pregnancy as leverage to gain access to the German military headquarters in order to gather intelligence information for the resistance.