He is married to (Not public).
They got married on May 4, 1949 at Soerabaja, he was 27 years old.Source 1
grandparents
parents
brothers/sisters
children
https://www.nationaalarchief.nl/onderzoeken/archief/2.10.50/invnr/439/file/NL-HaNA_2.10.50_439_0114
"United States, Social Security Numerical Identification Files (NUMIDENT), 1936-2007", , FamilySearch (https://www.familysearch.org/ark:/61903/1:1:6K3R-KGPL : Tue Feb 25 09:03:49 UTC 2025), Entry for Frederik Schoonderwal and Hendrik F Schoonderwal.