[1] Sasse was born in Paris to a wealthy Jewish family; one of four children, her sister Suzanne would later become a noted aviator.
[1][5] Sasse met Jean Moulin in November 1936 and assisted him with his work of establishing a French resistance movement.
[5] She was also part of the Gilbert network led by her brother-in-law, Colonel Georges Groussard, and coded and de-coded messages from the resistance to Charles de Gaulle in London.
[1] On her death in 1986, Sasse left her estate to the city of Paris for the establishment of the Musee Jean Moulin, which was opened in 1994.
She was later in a relationship with the poet Paul Geraldy, during which time Moulin asked her to marry him; she declined his proposal.