Wendy Anne Potter is the sister of Harry Potter Jr and the daughter of Harry Potter Sr. Shortly after her family moved to a new apartment building in San Francisco, she met Torok the Troll and was replaced by him. However, she was not killed, but kept in a kind of stasis. Torok intended her to become the Queen of the Fairies after he converted the building into a fairy world.
Torok infiltrated the Potter Family, using Wendy's form. They noted that her behavior was unusual, however. She also entered the apartments of their neighbors, turning each person into a part of her the fairy world.
However, her brother Harry, armed by Eunice St. Clair, entered the fairy world and found her in a magical glass case. He released her, and was soon attacked by a monster. The monster tried to kill Wendy, but Torok intervened, destroying his own monster to save her. This effectively defeated Torok. (Troll)