[3] At the age of 16, Stelmach was one of two Canadian entrants to the 1976 Women's World Open, held in England.

According to an article in Maclean's magazine in April 1979, Stelmach had never lost a match to another woman in Canada.

[3] In April 1981, Stelmach made the first half century by a woman in competition, on the way to winning her sixth Canadian Open title.

[6] Also in 1981, Stelmach and her playing partner Cliff Thorburn won the World Mixed Pairs Championship.

[5][7] Stelmach reached the final of the 1984 Amateur World Women's Snooker Championship, defeating Lynette Horsburgh 3–0, Maggie Beer 3–1, Gaye Jones 4–0 and then Caroline Walch 4–0.