After the end of the war, while still in Europe, Rosenfarb married the future nationally famous Canadian abortion activist Dr. Henry Morgentaler (the two divorced in 1975).

Morgentaler and Rosenfarb, pregnant with Goldie, their daughter, emigrated from Europe to Canada, landing in Montreal in the winter of 1950, to a reception of Yiddish writers at Windsor Station.

In 1972, she published what is considered to be her masterpiece, Der boim fun lebn (דער בוים פֿון לעבן), a three-volume novel detailing her experiences in the Łódź Ghetto, which appeared in English translation as The Tree of Life.

[1][2] Her other novels are Botshani (באָטשאַני), a prequel to The Tree of Life, which was issued in English as two volumes, Bociany (meaning Storks in the Polish language) and Of Lodz and Love; and Briv tsu Abrashen (בריוו צו אַבראַשען), or Letters to Abrasha (not yet translated).

For years, Rosenfarb exchanged letters with her childhood friend and fellow Holocaust survivor Zenia Larsson, who published her side of the correspondence in a collection entitled Brev Fran En Ny Verk Lighet (1972).