
| Willem Marinus Karel Boudewijn van Idsinga | |
| B: | 2 Sep 1868 |
| Veere, Zeeland, Netherlands | |
| D: | 4 Nov 1904 |
| Zeereis | |
![]() | Helena Catharina Kesper |
| Helena Catharina Kesper | |
| B: | 1 Mar 1874 |
| Amsterdam, Noord-Holland, Netherlands | |
| M: | 22 Feb 1900 |
| Arnhem, Gelderland, Netherlands | |
| D: | 4 Mar 1973 |
| Haarlem, Noord-Holland, Netherlands | |