Nadia struggled with the death of her sister and according to Jeanice Brooks, “he dichotomy between private grief and public strength was strongly characteristic of Boulanger’s frame of mind in the immediate aftermath of World War I. Guilt at surviving her talented sibling seems to have led to determination to deserve Lili’s death, which Nadia framed as redemptive sacrifice, by throwing herself into work and domestic responsibility: as Nadia wrote in her datebook in January 1919, 'I place this new year before you, my little beloved Lili–may it see me fulfill my duty towards you–so that it is less terrible for Mother and that I try to resemble you.'"