Gabriel Walvis was a son of Zacharias Walvis and Fijtje Posener. He married in Amsterdam on 20 June 1928 to Margaretha Verdoner, daughter of Mozes Verdoner and Betsy de Vries. The couple had two daughters: Sophia and Betsy, who, aswell as their mother, both have survived the Holocaust.
After the death of Gabriel's father Zacharias Walvis on 14 February 1925, his mother remarried on 28 March 1928…