Timms began her professional basketball career in 1984 in Australia, where women's basketball is very popular. In 1989, she became the first Australian woman to play internationally when she went to Germany to play with the Lotus Munchen team. While playing in Germany, she got a chance to play alongside Marlies Askamp, who would later also play with her on the Mercury. While there, she was named the Women's International Player of The Year in 1994 and 1996.
In '96 also, she helped the Australian national women's basketball team earn their first Olympic medal, earning Bronze at the Atlanta competition.
Upon the onset of the WNBA in 1997, she went to the Mercury, where she played in the WNBA finals in 1998, losing to the Houston Comets. In 2001, she announced her retirement and almost inmedately she joined the Mercury's television broadcasting crew, a job which she held only for that season. She averaged 4.0 assists and 4.6 points per game with the Mercury, her highest scoring average in one season being 12.1 points per game in 1997. On August 7, 2002, her jersey, number 7, became the first jersey to be retired by the Mercury.
On July of 2003, she announced she is pregnant, and expecting the baby to arrive in January of 2004.