Kestrel was born about two hundred and fifty years before the events of the Farseer Trilogy. She grew up on the coast of Buck; her father was a fisherman. She and her twin sister Gull both possessed the Skill and were very close to one another. Their mother described them as Lightning and Thunder for their personality differences. Both studied the Skill and became part of the Stanchion coterie, which served Queen Diligence Farseer.
Stanchion, their coterie leader, became romantically involved with both Gull and Kestrel. When Kestrel discovered this, she killed her sister with the Skill in a fit of rage. She later reflects that both relationships were more driven by lust and Skill-euphoria than any deep feeling.
As punishment for the murder of her sister, Kestrel's Skill was blocked and she was exiled. As Kestrel was strong in the Skill and had used it to achieve artificial health and longevity, despite general disapproval of the act, she would remain in exile for over two hundred and twenty years. Her inflated lifespan ensured that she outlived all the other members of her former coterie. Their fates were unknown to her, but she believed that they journeyed along the Skill-road to attempt to create a dragon, as the coterie had originally planned.
At some point, Kestrel learned of the religion of White Prophets and their Catalysts. The belief that Time would be conquered in the perfect world the White Prophets strive to create left a deep impression on her. She hoped against hope that the killing of her sister could thus be undone, and studied what information was available about White Prophets' histories and prophecies. Eventually, she joined a caravan on its way to Jhaampe to pursue a rumor that a White Prophet resided there.
In the Mountains, she finds the Fool and serve him in his hut. When the arrow-struck Fitz arrives at their door, she helps take care of him. She tries to needle Fitz and the Fool into fulfilling their fate. She quotes prophecies about the Unexpected Son, giving more information on the subject to Fitz than the Fool ever did.
When Kettricken organizes the expedition to locate her missing husband Verity, Kettle joins it. On the Skill Road she seems to gain strength and stamina though it might be that everyone else is affected to one degree or another by it except for her. Kettle helps Fitz deal with the mental strain of the black Skill Road and the Skill-attacks by Regal and his Coterie by teaching him the game of Stones, through progressively harder game-puzzles.
After they reunite with King Verity, Kettle promises to restore his Skill and take part in creating his dragon if Fitz heals her own Skill. With the help of the Fool and Nighteyes, Fitz accomplishes that and shows her her block is self inflicted for the most part as a result of her guilt and self hatred for what she did. He rekindles her memories and love for her twin sister, Gull and tells her her sister would surely forgive her for the sisters loved each other much more than either loved Stanchion.
With her Skill restored, Kettle restores Verity's Skill and they both go to the Silver stream and cover their arms in the Silver Skill. Kettle fills the dragon with her memories and love for her sister Gull, hoping in this way to undo in some measure her long ago crime.
Before she is completely absorbed into the dragon, Kettle imparts on Fitz two pieces of advice: that the mother he has deliberately forgotten loved him and that his love for Molly was a youthful folly that wouldn't have worked in the long term.
Kettle was strong in the Skill magic. She could kill with it, as few others can. She gained control of her body and therefore was rarely ill and lived to the age of two hundred and fifty. She healed Verity's mind after he killed with the Skill. She took part in the creation of Verity's Stone Dragon.
Kettle knows the entirety of the children's rhyme "Six Wise Men went to Jhaampe-town, climbed a hill and never came down,"
Kettle was well versed in the game of Stones which was used in her time as a tool to sharpen the minds of Skill-apprentices and their mental defenses.
Kettle studied the lore of the White Prophets and their prophecies during her exile.
Kettle is an able hunter.