Topham is best remembered for her four-medal performance at the 1991 Pan American Games in Havana, Cuba.

As a member of Canada's second-place women's team in the 4x100-metre freestyle relay, she also earned a silver medal.

At her international debut as a 15-year-old at the 1988 Summer Olympics in Seoul, South Korea, she competed in two events, advancing to the B Final of the 50-metre freestyle and placing twelfth overall, as well as swimming for the Canadian team in the preliminary heats of the 4x100-metre freestyle relay.

[1] When she won two golds at the 1991 Pan American Games, the Toronto Star listed her a Mississaugan.

In individual competition, she advanced to the B Finals of the 50-mtre freestyle and the 100-metre butterfly, placing tenth and fourteenth, respectively.