Janice Halliwell is the sister of Allen Halliwell. She is mentioned in "Witchstock" by Allen. It would seem that Allen's granddaughter Paige looks very similar to her as he thought that Paige was Janice for a moment. Not much is known about her except that she usually babysat Patty at her "pad".
Janice was mentioned in 1 episode throughout the series.
- Season 6