born: born: in Stokkar in Súrnadalur in Norway
died: at Þórdísarstaðir in Snæfellsnes in Iceland
married: Þorgrímur Þorsteinsson
married: Börkur Þorsteinsson
Þórdís was the sister of Gísli, the outlaw-hero of Gísla saga. Even before the family left Norway to settle in Iceland, Þórdís was the source of problems and conflict for Gísli. It was Þórdís who overheard Gísli recite a verse of poetry that strongly suggested that he was responsible for the killing of Þorgrímur, Þórdís' husband. Later, she voiced her suspicions to her husband's brother, Börkur (who had married Þórdís), which resulted in his prosecuting and pursuing Gísli.
Börkur, no hero, was not a courageous man. He paid Eyjólfur to track down and kill Gísli. Eyjólfur eventually caught up with Gísli, and his men overwhelmed Gísli with numbers. Gísli was killed.
In this passage from the saga, Þórdís shows that despite the many times she treated her brother with dishonor, she still retained a spark of decency. After he killed Gísli, Eyjólfur visited Helgafell, where Börkur and Þórdís lived. Börkur welcomed him warmly and asked Þórdís to offer lavish hospitality to the man. Þórdís did not wish to offer any but meager hospitality to her brother's killer.
And later in the evening, when she brought in the food, she dropped a tray of spoons. Eyjolf had laid Gisli's sword between the bench and his feet, and Thordis recognized it. When she bent down to pick up the spoons, she grabbed the sword by the hilt and thrust out at Eyjolf, meaning to strike him in the guts. But she had not noticed that the end of the hilt was turned upwards, and it caught against the table. She had struck him lower than she intended, hit him in the thigh and wounded him sorely. Bork grabbed hold of Thordis and wrenched the sword away from her, and the others jumped up and overturned the tables and the food.
Gísla saga, ch. 37
This episode of revenge is also described in Eyrbyggja saga, where there are a few more details. That text says that Börkur tried to strike his wife, but her young son, Snorri, pushed Börkur away. Þórdís declared herself divorced from Börkur on the spot, and Snorri later drove him out of their home at Helgafell.