Philip, Sientje and Catharina Theeboom were children, born in the 2nd marriage of Heintje van Bever and Aron Theeboom. That marriage was on 9 December 1936 in Amsterdam, after Heintje van Bever was divorced on 22 October 1935 from a non-Jewish husband, from whom she had a son Samson Poen. Philip and Sientje Theeboom as also their half-brother Samson Poen have been killed during the Shoah in Auschwitz. The in 1940 born Catharina Theeboom died in September in Amsterdam, just one month old.
Cith Archive of Amsterdam, archive cards of Heintje van Bever and Aron Theeboom.