In June 1940, an obituary was placed in the Nieuw Israëlietisch Weekblad for B. Broeks-Nijveen.
Nieuw Israëlietisch Weekblad, 21 June 1940
Bertha Mozes was a daughter of Israël Mozes Mozes and Rebekka de Vries. She was divorced from mister Broeks. She had four children: Jansje, Abraham (who both passed away before the war), Betje and Hendeltje.
Stadsarchief Amsterdam, archiefkaarten Bertha Mozes and Broeks
Presumably Bertha Mozes called herself Nijveen, like other members of the Mozes family.
Editors Digital Monument