Auer was born in
Zürich. Her father was the communist writer, Erich Vallentin. After her parents' untimely death in 1917, Judith was brought up by a well-to-do
Jewish family. She completed her
Abitur and began studies in
music in the hopes of becoming a
pianist. In 1924, as a student, she joined the
Young Communist League of Germany, and the next year, moved to Berlin. There, she met and married Erich Auer, a functionary in the
Communist Party of Germany (KPD), in 1926. In 1927, she joined the KPD. In 1928, Auer went to
Moscow with her husband and worked at the
Comintern's offices. In 1929, her daughter Ruth was born. To earn money, Auer learned
typing and
shorthand and took a job at a KPD establishment. ==Resistance activities==