Betsy Bartels was a daughter from the first wedding of her father Joel Bartels and Saartje Cohen, who passed away already on 5 February 1932.
City Archive of Amsterdam, archive card of Joel Bartels.
In addition, a Jokos file (number 40007) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.