Lysa Arryn

Lysa Arryn is a character in Game of Thrones. She has not been cast as yet, but is expected to first appear in the first season.

Lysa Arryn is the wife of Lord Jon Arryn and the younger daughter of Lord Hoster Tully. She is the younger sister of Lady Catelyn Stark. She has a young son, Robert Arryn.

In the books
In the Song of Ice and Fire novels Lysa is Catelyn's sister, who is distrustful of the Lannisters. She dotes on her son, possibly excessively.