Gerrit Veffer was a son of Jacob Veffer and Duifje Vuisje. He married in Amsterdam on 14 August 1940 to Elisabeth Roos. On 25 July 1943 their daughter Dora Catharina Veffer was born, who was however registered as Dora Catharina Maijer. She survived the Holocaust.
City Archive of Amsterdam, archive card of Gerrit Veffer.