Jonas Prins was a son of Jacques Prins and Aaltje Fresco. He married in 1913 in Den Haag to Roosje Koekoek, daughter of Elkan Koekoek and Sara van Creveld. The couple had also a married daughter Alida Viskoper-Prins who lived with her husband in Amsterdam.
Municipal Archive of Den Haag, index marria…
In addition, a Jokos file (number 15699) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.