Children |
 | 1. Wobbegien Koster, b. 03 February 1898, Musselkanaal, Onstwedde, Groningen, Nederland , d. Date unknown |
| 2. Jacob Koster, b. 30 May 1899, Musselkanaal, Onstwedde, Groningen, Nederland , d. 07 April 1900, Musselkanaal, Onstwedde, Groningen, Nederland (Age 0 years) |
 | 3. Jacob Koster, b. 18 February 1903, Musselkanaal, Onstwedde, Groningen, Nederland , d. Date unknown |
| 4. Derk Koster, b. 13 August 1904, Musselkanaal, Onstwedde, Groningen, Nederland , d. 17 April 1911, Ter Apelkanaal, Vlagtwedde, Groningen, Nederland (Age 6 years) |
 | 5. Annechiena Koster, b. 22 April 1906, Musselkanaal, Onstwedde, Groningen, Nederland , d. Date unknown |
| 6. Harm Koster, b. 24 April 1908, Ter Apelkanaal, Vlagtwedde, Groningen, Nederland , d. 25 October 1908, Ter Apelkanaal, Vlagtwedde, Groningen, Nederland (Age 0 years) |
 | 7. Alida Koster, b. 08 September 1909, Ter Apelkanaal, Vlagtwedde, Groningen, Nederland , d. Date unknown |
|