Queen Elizabeth I
From Jenny Everywhere Wiki
When the Queen of the Black Market told Wendy Severn that she was a little over 520 years old, Wendy boggled at the thought that this made her “older than Queen Elizabeth I”, suggesting Elizabeth existed as a historical figure in Wendy's home universe. (PROSE: The Grand Multiverse Hotel)
Behind the scenes
Being an actual historical figure, Elizabeth I can be considered a public-domain character in her own right.