Klaas Pieters Boonstra, born circa 1819, died before October 16, 1873, aged at most 54 years.

Klaas was married to
Jaaike Gerbens Zuiderbaan, born circa 1823 (?), died before October 16, 1873, aged at most 50 years.

• 1 : Tietje Boonstra, born in Grouw on September 30, 1846.
  Tietje was married in Utingeradeel on October 16, 1873, at the age of 27 to Wybe Atzes van der Ploeg (aged 27 years), born in Akkrum on April 11, 1846, son of Atze Aukes van der Ploeg (carpenter's man) and Jitske Wybes Feenstra (maid servant), died in Akkrum on December 24, 1923, aged 77 years.