Karolina Füllenbaum was a daughter of Simon Füllenbaum and Flora Delmonte. She married in Hannover on 16 January 1921 Arnold Machol, who however passed away there on 25 April 1928. She remarried only 22 June 1939 to Alfred David Henri Blok, a son of Jaob Blok and Mietje Zon.
City Archive of Amsterdam, archive cards of Karolina Füllenbaum and Alfred David Henri Blok.