Betty Cohen was a daughter of Samuel Louis Cohen and Frieda Gersons. She was born in 1914 in Den Haag and had a sister Rose Clara, born in Brussels in 1911. Betty Cohen married with the commercial representative David Samuel Polak from Maastricht, a son of Henri Samuel Polak and Grietje Sanders. Both have been killed on 23 September 1943 in Auschwitz.
Municipal Archive of Den Haag, family registration cards of David Samuel Polak and Samuel Louis Cohen and the certificates of death of Betty Cohen and David Samuel Polak, nrs. B713 and B712 dated 14 March 1949.