+---- Willem Jacobus van Gulik 1834-1910
+---- Willem Jacobus van Gulik ca 1871-1953
| +---- Margaretha Stoffelina Draaijer ca 1838-
+---- Robert Hans van Gulik
| | +---- Engelbertus de Ruiter
| +---- Bertha de Ruiter ca 1870-/1945
| +---- Bertha Kock
+---- Willem Robert van Gulik
| | +---- Chün-shao Shui
| +---- Shih-fang Shui
| +---- N.N. K'uai
==== Pieternella van Gulik
+---- Yvonne Maria Johanna Huizer
|