In The Cross, the final volume of the trilogy concerning her, her husband is killed and she enters a convent, where she dies in 1349 of the Black Plague.  
We see her contented childhood in The Bridal Wreath, but she marries unhappily in The Mistress of Husaby.  In The Cross, the final volume of the trilogy concerning her, her husband is killed and she enters a convent, where she dies in 1349 of the Black Plague.  FTP, identify this title character of three historical novels set in medieval Norway, for which the Nobel Prize in 1928 was awarded to Sigrid Undset.
We see her contented childhood in The Bridal Wreath, but she marries unhappily in The Mistress of Husaby.  
Kristin Lavransdatter