Janet Chant is the ward of Chrestomanci who comes from Twelve-B.
Janet was born to a family on Twelve-B (our world). Her younger brother died when he was a baby. Little is known about Janet's past life.
She was sent to Twelve-A by Cat Chant's older sister Gwendolen who wanted to use Janet to replace her at Chrestomanci Castle. She at first did not like Twelve-A and was shouted at by Michael Saunders because she couldn't answer questions during lessons correctly, such as the Battle of Agincourt and during geography, where she doesn't know that the continent across the Atlantic is called Atlantis. After Gwendolen entered another world, Janet asked Chrestomanci if she could become his ward. Janet went on holiday with Chrestomanci's family to the south of France and gained a horse obsession with Julia Chant after reading a book about horses. Janet also had an obsession with Carol Oneir's dreams, much to the dislike of the boys, who called Carol's dreams "slush".
Janet is described as the opposite of Gwendolen.