Big Sue

 was a human Earth woman.

She was a friend of Maddy Sharp. When she and Maddy and Maddy's adopted son were attacked by owls at a shopping mall, they were rescued by Iris Wildthyme. Maddy's son decided Iris was dangerous, and convinced Maddy and Big Sue to get him back to his father King Daedalus, promising they would be made young again as a reward. When Icarus was returned, Daedalus made Maddy thirty years younger and Big Sue into a baby. Their minds were wiped of recent events in the process, then Daedulus transported them back to Earth. (PROSE: The Blue Angel)

Behind the scenes
Like Iris Wildthyme, Big Sue and Nesta originate from a trilogy of novels by Paul Magrs set in the fictional Phoenix Court council estate.