Sybren Valk, born in Idaarderadeel on April 14, 1853, fisherman.

Sybren was married to
Fokje Helfrich, born on March 16, 1851.

• 1 : Jacobus Valk, born in Wartena on January 30, 1885, fisherman, died in Wartena on December 24, 1966, aged 81 years.
  Jacobus was married in Idaarderadeel on June 25, 1908, at the age of 23 to Aaltje Feenstra (aged 26 years), born in Wartena on October 10, 1881, daughter of Otte Gerrits Feenstra (barge hand and worker) and Hinke Hinnes de Jong, died in Wartena on November 4, 1966, aged 85 years.