[1][2] Born on 18 March 1858 on the island of Hrappsey in north-western Iceland, Katrín Sigríður Skúladóttir was the daughter of Skúli Þorvaldsson Sívertsson, a farmer, and his wife Hlíf Jónsdóttir.
They returned to Iceland the following year, settling in Sauðárkrókur after her husband received an appointment at the hospital in Skagafjörður.
Kartrín was also interested in medical work but the only training open to women in the healthcare field was for midwives, which she did not find attractive.
She also served on the board of Thorvaldsensfélag (the Thorvaldsen Association), Iceland's oldest women's organization established in 1875.
Katrín was one of four elected women who sat on Reykjavík's municipal council from 1908 to 1916, the other three being Bríet Bjarnhéðinsdóttir, Guðrún Björnsdóttir and Þórunn Jónassen.