Judik Stad was a daughter of Isaac Joel Stad and Marianne Stad-Scheffer. She married on 19 March 1919 to Joel Reens. Stadsarchief Amsterdam, archiefkaart Marianne Scheffer.
In addition, a Jokos file (number 32177) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.