In 1981, Pearson became one of the first athletes in Australia to attend the newly established Australian Institute of Sport (AIS). Pearson attend the AIS until 1986 and was named AIS Athlete of the Year in 1985.
At the 1982 Commonwealth Games in Brisbane, Pearson collected her first international medals, winning silver and bronze in the 400m and 200m individual medley respectively. Curry won both events.
Pearson had a good preparation for the 1984 Summer Olympics, after winning two events at the American Championships as a guest competitor. In the 200m individual medley, she trailed home the American duo of Tracy Caulkins and Nancy Hogshead, edging out Curry by 0.83s to claim the bronze medal. Pearson narrowly missed a second silver in the 200m freestyle, finishing in a time of 1m 59.79s, just 0.1s slower than the bronze medallist Annemarie Verstappen of the Netherlands. She also finished fifth in the 100m freestyle, which was won by Hogshead. She combined with Curry, Angela Russell and Anna McVann to finish fourth in the 4x100m freestyle relay.