Lady Penelope Creighton-Ward is a rich lady who lives in London. She owns a pink Rolls-Royce and has a butler named Parker. She was lonely through her childhood, as her parents lived in India. As she grew up, she decided to become a spy. She learned French, German, Spanish and Italian, and after many top-secret missions, she became Supreme Commander of the F.A.B. - Federal Agents' Bureau.
When she hears a message come through on her teapot communicator, she calls Parker and springs into action for International Rescue. Though she does not pilot a Thunderbird herself, she has been known to accompany the Tracy boys on a couple of missions - and her Rolls hides a few secrets in itself!
Lady Penelope's character is voiced by Sylvia Anderson in the hit TV show Thunderbirds. She is not really a main character, although her part in the plots of the stories she is in are quite big and valuable to the International Rescue service.