Jansje and Branca Koren were daughters of Israël Koren and Betje Polak. Jansje was born on 7 January 1895 and Branca on 13 June 1898, both in Amsterdam. They had a brother Isaac, who was born in 1893, but after his divorce he left for Kaapstad in South Africa in 1929. Their mother Betje Polak had died already in 1905 and their father remarried then Rosette Mozes and after her passing, again to Sellie Eljon. Their father passed away before the war, in 1937.
Jansje Koren was married in Nijmegen on 4 May 1934 to the non-Jewish Reijnier Hubertus van de Vijver, from whom she divorced there on 3 Februray 1941. Between August 1939 and November 1939 Jansje lived at two addresses in Den Haag: the Van Neckstraat 51 and in the Frankenstraat 90. Thereafter she moved to Amsterdam where she lived [per 27 November 1939 at Krammerstraat 54 1st floor .
Branca Koren remained unmarried. She lived among others at Zandvoort but per 15 October 1928 in Amsterdam at Lomanstraat 60 upperhouse and per 11 May till 29 April 1941 at Krammerstraat 38 ground floor. That date in April 1941 she moved in with her sister Jansje, who lived in the same street at no. 54 1st floor.
On 9 October 1943 Jansje and Branca Koren were locked in at Westerbork in the penal barrack 67. It might have been that they had made attempts to go into hiding or that they were already in hiding and betrayed. Ten days later, on 19 October, they were put on transport to Auschwitz where Jansje and Branca after arrival there on 22 October 1943 immediately were killed in the gas chambers of Auschwitz-Birkenau.
Sources include the City Archive of Amsterdam, family registration cards of Israël Koren; archive cards of Jansje Koren and Branca Koren; residence cards Lomanstraat 60 and Krammerstraat 38 of Amsterdam; the Municipal Archive of Den Haag, family registration cards/Peoples Registry of Jansje Koren; the file cabinet of the Jewish Council, registration cards of Jansje Koren and Branca Koren and the Wikipedia website jodentransporten vanuit Nederland.nl.