The Lady of the Green Kirtle / Queen of Underland Timeline and Summary

As the serpent/beautiful lady in green, she features in the owl's story of the lost prince.
The Lady of the Green Kirtle meets Jill, Eustace, and Puddleglum on the giants' bridge and tells them of Harfang. She gives them the double-edged message to deliver upon arrival.
She appears as the Queen of Underland after Rilian is released from the Silver Chair and his enchantment.
The Queen attempts to enchant Jill, Eustace, Puddleglum, and Rilian with her green powder and music.
When this doesn't work, she morphs into the green serpent and attacks them. Rilian kills her.
The Dwarves of Narnia confirm that she is of the White Witch's stock.