Joanna Duchamp is a young member of the Duchamp Coven. Her Familiar is Letita and her Implement is a buckler. Her mother ordered her to send her familiar after Blake Thorburn, who gave her back after defeating her. She later appears to bargain with Maggie Holt along with her sister.
Later events reveal that the real Joanna Duchamp is inside a Faerie House, having been spirited away and kept captive by Padraic and his companions for the last two to three years before her tenth birthday, while one of them take her place.
Straight blonde hair like all Duchamps, although she was wearing leggings at the time and a jacket.