Sigrid Bielke was the daughter of Nils Bielke from Åkerö and Catharina Oxenstierna and in 1643 married the general and rigsmarsk Count Gustaf Horn of Björneborg. Sigrid Bielke, who was Gustaf Horn’s second wife and stepmother to Agneta Horn, was widowed in 1657.
Like many of her female contemporaries from the aristocracy, she recorded important events such as births, christenings, weddings, deaths, and funerals in a genealogical record, which is published in Personhistorisk tidskrift, 1st vol., 1898-1899, under the title Sigrid Bielkes (...) egenhändiga annotationer om sina närmaste anförvandter. The records date from 1548 up to, and including, 1674 and not only contain records of her own relatives, but also on the family of her husband Gustaf Horn. Sigrid Bielke recorded the birth of her step-daughter Agneta Horn and the death of her mother. Her most moving accounts are the reports of her children’s deaths: seven of Sigrid Bielke’s nine children died in infancy.