The Merry Wives of Windsor by William Shakespeare.
They're the "witches" in the book A Wrinkle in Time. It might be more appropriate to ask WHAT they are; at one point in the story it's implied that they are the "ghosts" of stars.
Mrs Tonks (Andromeda) did not die.
233
This event happened on pages 736 and 737 of the hardback version.