McIlrath was, with Fran Lovis, one of two of the dominant players in Australian snooker in the 1970s and 1980s.[2]
The 1980 Women's World Open, recognised as the world championship for women was sponsored by Guinness, and held at Hayling Island.[3] There were 45 entrants, and a record winner's prize for women's snooker, £700. In the last 16, McIlrath defeated Sue LeMaich 3–1; in the quarter-final she won 3–1 against Maryann McConnell 3–1; and she reached the final by defeating Ann Johnson 3–1 in the semi-final.[4] Her opponent in the final, Agnes Davies, was aged 60 at the time, and went on to have a playing career spanning a total of 64 years. McIrath won the match 4–2 to capture the title.[3][4]
The victory, in only the second Women's World Open Championship (following the first held in 1976), made McIlrath the first non-UK player to win. Coincidentally, Cliff Thorburn became the first non-UK winner of the men's World Snooker Championship the same year. McIllrath remains one of only two non-UK World Women's Snooker Championship winners. Ng On-yee, who won her first title in 2015, is the other.[5]
At the 1981 world championships, McIrath lost in the quarter-finals to Sue Foster, and in 1983 she lost 5–6 in the semi-final, again to Foster.
