Erna Marx, née Eisenburg was the daughter of the Kissingen cattle dealer Oscar Eisenburg and his wife Rose who came from the long-established Jewish Kissinger family. Erna was born in Bad Kissingen on April 29, 1900. 

In 1923, in Würzburg, she married her second-degree cousin Wilhelm Marx who had been born in Krefeld in 1889 as the son of Rudolf Marx and his wife Sara. After their marriage, Erna and Wilhelm Marx moved to Hamburg where Wilhelm decided that he wanted to be economically independent and self-employed. In Hamburg, their first son Ernest was born in 1924. Some years later, Wilhelm Marx made up his mind to go to Cologne and work in his parents’ firm as a partner. A short time after their arrival in Cologne, the second son Herbert was born in April 1927.

In the Pogrom Night of 1938, Erna’s husband was arrested and imprisoned in Dachau Concentration Camp for six weeks. After his release, he succeeded in getting a visa for Australia for himself and his family. In May 1939, Erna and Wilhelm Marx emigrated to Australia with their sons Ernest and Herbert, where they settled in Sidney. At the beginning, life on the Fifth Continent was rather difficult for the Marx family. Their situation became a little bit easier because of the financial support Erna got from her brother Max who had been living in Argentine for some years. In order to further boost the economic situation of the family, Erna Marx founded a firm for costume jewelry. Later, she helped her son Ernest in his clothing factory. He was so successful with it that he could give jobs to twenty employees in its heyday.

Her husband went self-employed as a real estate agent and died in Sidney in 1961. Erna outlived him by seven years. She also died in Sidney on April 26, 1968, three days before her 68^th birthday.