She got to know Brecht in 1922, the same year she came to Berlin. She worked as a secretary for the German-American poet and writer, Herman George Scheffauer. She began collaborating with Brecht in 1924, and is listed as co-author of The Threepenny Opera (1928).
She purportedly wrote the majority of the text as well as providing a German translation of John Gay's The Beggar's Opera, on which the musical play is based, as working material for Brecht and Kurt Weill, the composer. She reportedly wrote at least half of the Mahagonny-Songspiel, but was not credited. She was the main text author of the musical comedy Happy End (1929).
After Brecht's death in 1956, she published works of his at Suhrkamp Verlag, a German publishing house, and worked as a dramaturg for the Berlin Ensemble. She made a German version of He hanshan (The Confronted undershirt), a Yuan Dynasty-era Chinese play.