Brownsdon competed at the 1988 Summer Olympics in Seoul, where she reached the B Final of the 100-metre breaststroke, placing 16th overall. In the 200-metre breaststroke and 400-metre individual medley events, she was eliminated in the heats, placing 20th and 18th overall. later that year, she won US Open titles in the 100-metre breaststroke and 4x100-metre medley relay. In 1989, she reached both breaststroke finals at the European Championships for the third consecutive time, finishing eighth in both. At the 1990 Commonwealth Games as part of the England team, she took her Commonwealth medal tally to five, winning a bronze medal in the 100-metre breaststroke final and a silver medal in the 4x100-metre medley relay, with Joanne Deakins, Madeleine Scarborough and Karen Pickering, replicating her achievements from the 1982 Games. She also finished sixth in the 200-metre breaststroke final.