Sjoerd Bijlsma, born circa 1870 (?).

Sjoerd was married to
Trijntje Koopmans, born circa 1874 (?).

• 1 : Elisabeth Bijlsma, born in Harlingen on February 1, 1897, died in the year 1988, aged 91 years.
  Elisabeth was married in Harlingen on July 31, 1924, at the age of 27 to Haaije Tigchelaar (aged 26 years), born in Harlingen on March 30, 1898, son of Sikke Tigchelaar (merchant in patotoes and vegetables) and Geertruida Catharina Busser, clerk, died in the year 1979, aged 81 years.
  

• 2 : Rinske Bijlsma, born on February 17, 1901, died on September 22, 1986, aged 85 years.
  Rinske was married in Harlingen on May 4, 1927, at the age of 26 to Simon Tigchelaar (aged 27 years), born in Harlingen on April 22, 1900, son of Sikke Tigchelaar (merchant in patotoes and vegetables) and Foekje Posthuma, stuurman grote handelsvaart, died on May 17, 1982, aged 82 years.