Neeltje Koster married Isaäc Boeken in 1901 in Amsterdam. Before that time she already had two children, among whom Jacob. With Isaäc Boeken she had another four children: Branca, Hermanus, Esther and a child that survived the war. Jacob, Aaltje and Sara were her stepchildren.
Stadsarchief Amsterdam, archiefkaart Isaäc Boeken
In addition, a Jokos file (number 31402) on this person is at the Amste…