Moo is the leader of the King's Gambling Board and works for the British Spy intelligence agency known as the SIS. Before she was known as Moo, she was called Lady Silvia Stone. By chance she met Mr. Rakshasas, who was part of the British SIS in India at the time, and joined the MI5 and later M16.
Moo was an old friend of Nimrod, and is one of the few people in the world that know he is a djinn. She takes up a primary role in the The Five Fakirs of Faizabad and became good friends with John and Philippa.
Moo saw reports that bad luck was spreading in the news paper. She went to nimrod and the Tuchemeter was recording the wrong luck and bad luck was spreading. Iblis Teer was well known for such treachery and was instantly suspected for sabotage and bad luck as the Ifrit were known for.