Sansa Stark from A Feast for Crows is the oldest daughter of the now deceased Ned Stark. She's been held against her will in the Lannister castle at Kings Landing. She was originally promised to be married to Geoffrey, which would one day make her queen. However, because of her father's supposed betrayal, Geoffrey's mother, Cersei finds him a more 'suitable' match, releasing Sansa from the awful task of being Geoffrey's wife. Sansa, in this book, is shown to have stronger character and inner faith than she had in previous books. She's cunning, able to make plans to get away, and she is able to play the system long enough to leave the castle with Peytr Baelish.
