Jillian won a Gold medal at the 1982 Commonwealth games as a member of the 4 x 400 meter relay team. She repeated that feat at the 1986 Commonwealth games, as well a winning a silver in the 400 meters. She was a member of the 4 x 400 metre relay that took a silver medal in the 1983 Pan Am Games. She won a silver in the 400 meters at the 1987 Pan Am games, and as part of the Canadian 4 x 400 meter relay team. She took a gold medal in the 400 metres and a silver medal in the 4 x 400 metre relay at the Francophone Games in 1989. She finish 5th in the 400 meter final at the 1992 Olympics in Barcelona.