Sietske Feenstra, born in Leeuwarden on April 4, 1898, daughter of Otte Baukes Feenstra (baker) and Iemkje Leenderts Algera.

Sietske was married in Leeuwarden on March 26, 1924, at the age of 25 to
Sj. Mendel (aged approximately 26 years), born circa 1898 (?).