Tobin was born in Bathurst and grew up in the Illawarra, where she attended Oak Flats High School.

[2] While still a teenager she made back-to-back quarter-finals in the women's doubles at the Australian Open, partnering Kerryn Pratt in 1977 and Leanne Harrison in 1978.

[3] In Grand Slam competition she twice came up against Martina Navratilova, who on both occasions went on to win the event, at the 1981 Australian Open and 1986 Wimbledon Championships.

Her best performances include making the quarter-finals of the singles draw at the NSW Open in 1977 and also Adelaide in 1980, as well as semi-final appearances in doubles at Perth in 1981 and Tokyo in 1986.

She has the distinction of being the last player to beat Evonne Goolagong Cawley on tour, which she did at the 1985 Australian Indoor tournament, ending the career of the former world number one.