Gertrud Schönbron was a daughter of Anton Schönbron and Selma Rosenbaum.
City Archive of Amsterdam, archive card of Gertrud Schönbron.
In J. Schelvis, Vernietigingskamp Sobibor (Amsterdam 1993) it is mentioned on page 181 that Gertrud Schönborn was the young woman who was called 'Loeka' by the leader of the rebellion in Sobibor in October 1943.