During her adolescence, Thévenet studied at the Saint-Pierre-les-Nonnains convent. The French Revolution saw the destruction of the old government and the formation of a new one that soon led to a violent massacre in her hometown in which two of her brothers were guillotineed in public on 5 January 1794. Her brothers died forgiving their killers and the pair beseeched their distraught sister to do the same - their final words to her were: "Forgive them as we forgive".