Joy Hill is the bastard daughter of Ser Gerion Lannister, who fathered her on a common woman named Briony.
Appearance and Character[]
She is described as a sweet child, but lonely, ever since her father's disappearance.
Books[]
A Storm of Swords[]
As part of the pact between Lord Tywin Lannister and Lord Walder Frey, Joy was to marry one of Walder's natural sons.
A Feast for Crows[]
When Ser Jaime Lannister talks with Sybell Spicer, she tells him that Tywin had promised her son, Ser Raynald Westerling, would be married to a bride from Casterly Rock, saying that Raynald would be given joy of him.
Jaime interprets as this meaning that Tywin was intending to marry Joy to Raynald, but the accuracy of this is questionable, as Joy had already been promised to Lord Walder Frey in exchange for his help during the Red Wedding.