Lady Olenna Tyrell from A Storm of Swords is the grandmother of Margery Tyrell. She is cunning and intelligent. She is also compassionate toward Sansa. She invites Sansa to have some snacks with her in the courtyard one day and asks her what Joffrey really is like. Sansa tells her everything and tells her that Joffrey is a monster. The wedding goes on, however, but in the meantime, Sir Dontos has given Sansa an amethyst hairnet to wear to the wedding. During the festivities, Lady Olena plucks one of the amethysts from Sansa's hairnet and poisons Joffrey. It was not an ameythyst but some poisonous berry.
