During the incarceration, Catherine gave birth first to her eldest daughter Isabella of Finland in 1564 (died 1566), then to her son Sigismund in 1566, and finally her youngest child Anna of Finland on 17 May 1568.
During the incarceration, Catherine gave birth first to her eldest daughter Isabella of Finland in 1564 (died 1566), then to her son Sigismund in 1566. For some reason, her youngest child Anna of Finland is also reported in several sources to have been born in Gripsholm, though she was born on 17 May 1568.