Who is Sybil Partridge?

Sybil Partridge is a fictional character from the 1955 novel "The Riddle of the Sands" by Erskine Childers, known for its themes of espionage and adventure. She is not a prominent figure in popular literature or media, and there may be some confusion with other characters or real-life individuals of similar names. If you are referring to a specific context or medium, please provide additional details for a more accurate answer.