Siegfried Kraal married Pieternella Wilhemina Johanna van Egmond in 1920. She died in 1929 in France. Siegfried married again with Margrit Laszlo in 1932. Together they had a son, Peter Kraal.
Stadsarchief Amsterdam, archiefkaart Siegfried Kraal
In addition, a Jokos file (number 50152) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.