Gerardus Cats was a son of Barend Cats and the non-Jewish Johanna Martina Kool. Gerardus' father was previously married to Bertha Hachgenberg, who however passed away on 21 April 1915 and he remarried again on 31 July 1918.
From that 1st marriage, Gerardus Cats had two sisters (a twin), namely Johanna who married in 1930 and survived the war and Barendina, who was married too but who was killed in…