Gabriel Walvis was a son of Levie Walvis and Judik Cohen de Korte. He married in Amsterdam on 16 February 1905 to Rosette Degen, daughter of Levie Degen and Eva Bleekveld. The couple had 3 children Levie, Eva and Salomon, who all did not survive the war.
City Archive of Amsterdam, archive card of Gabriel Walvis and website www.wiewaswie.nl.