Gertrud Marcus was in de eerste echt gehuwd met Sally Winter. Na scheiding trouwde zij in 1931 met Frits Seelenfreund, van wie zij zich in 1939 liet scheiden. Stadsarchief Amsterdam; Archiefkaart van Gertrud Marcus
Fritz Seelenfreund managed to flee to Shanghai before the war. In the Red Cross Archives many documents testify to the fact that Fritz tried to apply for Japanese citizenship both for himself and the children. (File number 119.483)