Saartje van de Giessen was the sixth child of Salomon van de Giessen and Hanna Noot. Her brother Hermanus was the youngest of the nine children of the family, of whom already two have died before the war and three have survived the Holocaust. Their father Salomon was arrested during the big raid of 2 October 1942 in Amsterdam and sent to Westerbork where he that same day was put on transport to Auschwitz. On arrival there on 5 October 1942 he was immediately killed.
Their mother Hanna Noot and the twin-sister of Saartje, Jetje van de Giessen probably have gone into hiding. They were brought to Westerbork 9 March 1944 and both put on transport as a penal case to Auschwitz on 19 May. Mother Hanna was immediately killed on arrival in Auschwitz on 22 May 1944. Jetje van de Giessen however most likely was still selected for forced labor. Her official date of death has been established as 30 September 1944 in Mid Europe as it was not possible to determine when and where exactly Jetje van de Giessen has lost her life.
Saartje and Hermanus van de Giessen were both inhabitants of the Centraal Israëlitische Krankzinnigengesticht Het Apeldoornse Bos (Israëlitic Mental Hospital). Saartje was taken in there 2 November 1931 and Hermanus on 26 June 1933. When in the night of 21 to 22 January 1943 the Germans "emptied" the Apeldoornse Bos, patients and nurses were sent in cattle wagons to Auschwitz, where almost everybody was killed immediately upon arrival. Among them were also Saartje and Hermanus van de Giessen, who on arrival there on 25 January 1943 immediately were killed.
City Archive fo Amsterdam, archive cards of Salomon van de Giessen, Saartje van de Giessen and Hermanus van de Giessen and the file cabinet of the Jewish Council, registration cards of Saartje van de Giessen and Hermanus van de Giessen.