Rebecca Zak was a daughter of Machiel Zak and Judith Olivier. She married in Amsterdam on 5 August 1925 to Levie Kunstenaar, a son of Emanuel Kunstenaar and Machteld Peereboom. The couple had no children.
Rebecca was born in a family with twelve children. Two of them have died in childhood. The other children have all been killed during the Holocaust.
City Archive of Amsterdam, family registration cards of Machiel Zak and Levie Kunstenaar and archive card of Levie Kunstenaar.