Engelina van Weren was the widow of Isaac Maandag. She was the mother of Betsy.
Stadsarchief Amsterdam, archiefkaart Betsy Maandag
In addition, a Jokos file (number 35714) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.The Jokos file reveals that a claim was lodged for compensation for looted jewellery (S-claim, number 15/358).