Her second long-term partner was 19 years older. She lived with Stanislaw Stempowski in a common-law marriage until the outbreak of World War II. During the occupation of Poland she stayed in Warsaw and supported the culture life of the Polish underground. At about that time, she also met Anna and Jerzy Kowalski, two married writers. They had a child in 1946, but Jerzy died in 1948. The two women stayed in a relationship for the next 20 years, although Maria tried to get Anna married again.