Sophia Vreeland was the widow of Simon Korper (08-12-1892/29-12-1934). She also had a son Philip.
Stadsarchief Amsterdam, archiefkaart Philip Korper
In addition, a Jokos file (number 2807) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.