Margaretha de Waart-Eljon, 'Greta', was born in Amsterdam on 29 November 1896 and was trained as a diamond worker. In 1924 she married the non-Jewish hairdresser Hendrikus de Waart. She had three children: Max, Maria Martina and Paula. The family moved to Velsen in 1934, to Haarlem in 1938 and to Roerdompstraat 13 on 8 April 1940.
Margaretha took in her nephew Jack Eljon, born in 1937, because he was not safe with his Jewish parents. After the raid of August 1942 he was taken to a foster family in Zeist under another name. He survived the war. In February 1943 the family had to move to Amsterdam. On 8 September 1943 Margaretha was stopped close to her home because she did not wear the yellow star. She was locked up, taken to the Hollandsche Schouwburg and then to the Vught camp. On 15 November 1943 she was deported to Auschwitz, where she was murdered on 31 January 1944 at the latest. She was 47.