The sorceress, daughter of Belgarath, in David Eddings' two series, The Belgariad and The Malloreon. Additionally, she appears in the two companion novels, Belgarath the Sorcerer, and, not surprisingly, Polgara the Sorceress.
Polgara is, in the present of these novels, a whopping three thousand years old. Sharp-tongued and sharp-witted, she rebukes men for any number of things, though she ends up being rather close with the blacksmith Durnik.
Polgara's destiny, essentially, is to keep the lineage safe that will eventually produce the boy to become the King of Riva, who will take the throne and confront the evil one-eyed god Torak.
Although very traditional fantasy, Eddings' books are captivating, and Polgara's sarcasm and cynicism always bring a breath of fresh air to what might otherwise be a very stuffy series of lore with orbs and monsters.
Incidentally, David Eddings begins crediting his wife, Leigh, after a time, and apologizes for not having credited her before. Suddenly, the flash of insight arrives as to how he managed to so cleverly characterize her.