Sybren Jacobs Postma, born circa 1821, died before May 5, 1910, aged at most 89 years.

Sybren was married to
Tjitske Gjalts Kuperus, born circa 1828 (?), died before May 5, 1910, aged at most 82 years.

• 1 : Franke Postma, born in Rauwerd on November 22, 1851, died in Leeuwarden on August 19, 1929, aged 77 years.
  Franke was married in Rauwerderhem on May 5, 1910, at the age of 58 to Geertje Feenstra (aged 44 years), born in Rauwerd on October 6, 1865, daughter of Keimpe Ottes Feenstra (shopkeeper) and Geertje Tjipkes van der Heide, died in Rauwerd on July 28, 1933, aged 67 years.
  Geertje was married before in Rauwerderhem on November 12, 1891, at the age of 26 to Wabe Wieringa (aged 28 years), born in Terzool on February 18, 1863, son of Freerk Willems Wieringa (worker) and Willemke Gerrits Strikwerda, coachman, worker, gardener and coachman, died in Rauwerd on April 22, 1904, aged 41 years.