One of the top European female freestyle swimmers right after the World War II, Irma Schuhmacher (later Heijting) competed at four major international tournaments during her career – at the 1948 and 1952 Olympics and at the 1947 and 1950 European Championships. The high point of her career was probably at the 1950 European Championships, where she won golds in the 100 m freestyle and 4x100 m freestyle relay and silver in the 400 freestyle. At the 1947 European Championships, Schuhmacher won 4x100 free relay silver and at the 1948 and 1952 Olympics, she won relay bronze and silver, respectively, while finishing sixth in the 100 free at both Olympics.
In 1950, while touring in Australia with another Dutch swimming star, Geertje Wielema, Schuhmacher met a young Dutch animal husbandry expert Johan Heijting, who had emigrated to Australia in 1949 from newly independent Indonesia, which was formerly a Dutch colony. They got married a few months before the 1952 Olympics and one week after the Olympics, Irma Heijting left Europe to join her husband on his farm in Queensland near Brisbane, where he bred sheep and cattle.