Freeman was the first ever Aboriginal Commonwealth Games gold medalist at age 16 in 1990. 1994 was her breakthrough season. At the 1994 Commonwealth Games in Canada, Freeman won gold in both the 200 m and 400 m. She also won the silver medal in the 1996 Olympics and came first at the 1997 World Champion in the 400 m event. 1998 saw Freeman taking a break from running due to injury. She returned to form with a first place in the 400 m at the 1999 World Championships. She announced her retirement from athletics in 2003.
Freeman was born in Slade Point, Mackay, Queensland, where the local athletics track is now named after her. Her coach throughout her athletic career was Peter Fortune. In 1999, she married Sandy Bodecker, separating in February 2003. In 2009, she married James Murch, with whom she gave birth to a girl in 2011. In 1998, she was awarded Australian of the Year, in 2001 the World Sportswoman of the Year and the Medal of the Order of Australia.
In 1987, Freeman moved on to Kooralbyn International School to be coached professionally by Romanian Mike Danila, who became her first real coach and later a key influence throughout her career; he provided a strict training regime for the young athlete.
In 1988, she was awarded a scholarship to an exclusive girls' school, Fairholme College in Toowoomba. In a competition in 1989, Freeman ran 11.67s in the 100 metres and Danila began to think about entering her in the Commonwealth Games Trials in Sydney.
In 1990, Freeman was chosen as a member of Australia's 4 × 100 m relay team for the 1990 Commonwealth Games in Auckland, New Zealand. The team won the gold medal, making Freeman the first ever Aboriginal Commonwealth Games gold medallist, as well as one of the youngest, at 16 years old. She moved to Melbourne in 1990s after the Auckland Commonwealth Games. Shortly after moving to Melbourne, Bideau her manager introduced Freeman to athletics coach, Peter Fortune who would become Freeman's coach for the rest of her career. She was then selected to represent Australia at the 1990 World Junior Championships in Athletics in Plovdiv, Bulgaria. There, she reached the semi-finals of the 100 m and placed fifth in the final of the 400 m.
Freeman competed in her second World Junior Championships in Seoul, South Korea. She competed only in the 200 m, winning the silver medal behind China's Hu Ling. Also in 1992, she travelled to her first Olympic Games, reaching the second round of her new speciality event; the 400 metres. At the 1993 World Championships in Athletics, Freeman competed in the 200 m, reaching the semi-finals.
1994 was Freeman's breakthrough season, when she entered into the world's elite for the first time. Competing at the 1994 Commonwealth Games in Canada, Freeman won gold in both the 200 m and 400 m. She also competed as a member of Australia's 4x100 m squad, winning the silver medal and as a member of the 4x400 m team, who finished first but were later disqualified. During the 1994 season, Freeman took 1.3 seconds from her 400 m personal best, achieving 50.04 seconds. She also set all-time personal bests in the 100 m (11.24) and 200 m (22.25).
Although a medal favourite at the 1995 World Championships in Athletics in Sweden, Freeman finished fourth. She also reached the semi-finals of the 200 m.
Freeman made more progress during the 1996 season, setting many personal bests and Australian records. By this stage, she was the biggest challenger to France's Marie-José Pérec at the 1996 Olympics. She eventually took the silver medal behind Pérec, in an Australian record of 48.63 seconds. This is still the sixth fastest time ever and the second fastest since the world record was set in Canberra, Australia in 1985. Only Sanya Richards-Ross has come within a quarter of a second of Freeman's time since. Pérec's winning time of 48.25 is the Olympic record and the third fastest ever.
In 1997, Freeman won the 400 m at the World Championships in Athens, with a time of 49.77 seconds. Her only loss in the 400 m that season was in Oslo where she injured her foot.
Freeman took a break for the 1998 season, due to injury. Upon her return to the track in 1999, Freeman did not lose a single 400 m race, including at the World Championships.
Throughout her career, Freeman regularly competed in the Victorian Athletic League where she won two 400 m races at the Stawell Gift Carnival. Freeman did not compete during the 2001 season. In 2002, she returned to the track to compete as a member of Australia's victorious 4x400 m relay team at the 2002 Commonwealth Games.
Freeman announced her retirement in 2003.
Since retiring from athletics Freeman has become involved in a range of community and charitable activities. She is an Ambassador of the Australian Indigenous Education Foundation.
Freeman was appointed as an Ambassador for Cottage by the Sea, alongisde celebrity chef Curtis Stone and big wave surfer Jeff Rowley. Cottage by the Sea is one of Australia's oldest charities and each year provides short-term beachside holidays and respite care for more than 900 children and families in need.