 Johnston placed eighth in the 50m rifle three positions and ninth in the 10m air rifle.In 1997 she beat her personal bests in all three events at the Oceania Championships in Adelaide where she placed fourth in the 50m rifle prone, tenth in the 10m air rifle and eleventh in 50m rifle three positions event.At the 1998 Commonwealth Games in Kuala Lumpur, Johnston won the bronze medal in the women's 50m prone event.