Lili and her older sister Nadia (1887-1979) were born into a distinguished family: their father Ernest was a violin professor at the Paris Conservatoire whose parents and grandparents had likewise been important musicians, and their mother was a Russian princess who married her singing teacher. Both sisters attended the Paris Conservatoire and both sought to win the prestigious prix de Rome in composition. Nadia entered the competition four times but never got beyond the second prize. Lili, whose early works had already attracted critical attention, took the 1913 prize with her cantata Faust et Hélène—a composition which was singled out by the jury as "beyond compare" and which still stands out as one of the best cantatas in the history of the Rome prize. News of this signal victory by a young woman composer spread quickly through Europe and across the Atlantic.

When Lili arrived in Rome she was already very well known. From early in her life she suffered from a variety of conditions we now identify as the hereditary Crohn’s disease, complicated at the end by tuberculosis. This condition forced her to return early from Rome to Paris and in early 1918 it became necessary to move her from Paris to escape the German bombardments. Friends and family continually ferried medical supplies out of town, including ice, a precious commodity in wartime, to reduce her fever. She died in March of 1918.

Among the two dozen or so works she left to posterity are songs and lyric scenes, a pair of fine pieces for solo piano, three psalm settings including the masterpiece Du fond de l’abîme (Psalm 130: "Out of the depths I cry to thee"), and a Pie Jesu she dictated to her sister in her last weeks, probably intended for a full Requiem mass. Her works for orchestra stand as some of the most elegant tone poems ever written.