Kaatje was the sister of Mietje Frenk. She was head of housekeeping services at the Jewish hospital in Rotterdam, where Mietje was the director. Their family was Orthodox. Both sisters were unmarried.
Kaatje and Mietje went into hiding in a holiday cottage at Coldenhove. Caught during a raid by the Sicherheitspolizei on 12 June 1944, they were probably betrayed.
Person is in the National Database of Victims of Persecution