Sara Bamberger was born in Bad Kissingen on March 10, 1873 as the daughter of the Kissingen Rabbi Moses Löb Bamberger and his wife Esther, née Goldschmidt.

She married the timber trader Sandor Shmaya Rosenbaum. They had four children who were all born between 1899 and 1902 in Budapest. In 1904, she and her four children once again lived with her mother in Bad Kissingen, Maxstrasse 5 from March till November. Since the year after that, the family lived in Frankfort where their son Moses died at the age of 19. At least since 1933, the Rosenbaum couple lived in Strasbourg. Both of them died there in 1940, details are not known.

Their son Marcel survived the Nazi Era and died in Paris in 1968. Their daughter Judith had got her doctorate at Johann-Wolfgang-von-Goethe University of Frankfort and married the Würzburg lawyer Dr. Isidor Grunfeld. During the Nazi Era, the young couple first moved to her parents in Strasbourg, then emigrated to Palestine. Then they went to London and organized children’s transports of Jewish children out of Germany from there. Judith Grunfeld became famous as the headmistress of a school in Shefford, Bedfordshire which gave shelter to hundreds of Jewish child refugees and educated them according to orthodox Judaism.