Gerrit de Leeuw was a son of Alexander Louis de Leeuw and Barto de Jong. He married on 26 August 1931 in Amsterdam to Branca Montahes. They had two children together, who, just as their mother, have survived the Holocaust.
City Archive of Amsterdam, archivecard of Gerrit de Leeuw and Alexander Louis…
In addition, a Jokos file (number 15295) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.