She was arrested on 3 August 1915 and charged with harbouring Allied soldiers. She had been betrayed by Georges Gaston Quien, who was later convicted by a French court as a collaborator. She was held in Saint-Gilles prison for ten weeks, the last two of which were spent in solitary confinement. She made three depositions to the German police (on 8, 18 and 22 August), admitting that she had been instrumental in conveying about 60 British and 15 French soldiers, as well as about 100 French and Belgian civilians of military age, to the frontier and had sheltered most of them in her house.