Dr Brett was raised in Perth, Australia and earned her veterinary degree from Murdoch University in 1986. After graduation, she spent time in a mixed animal practice in South West Western Australia. Afterwards, she moved north to Dongara for three and a half years to work in a mixed practice and spent time working as a barmaid, sheep roustabout, and freight deliverer. 

She then took a three month locum position in Kununurra, a northern border town in the Kimberley, and hasn't left in the last thirty three years! The practice is mixed but mostly small animal. They also have a satellite practice 100 km away. Dr Brett has had a long-standing interest in wildlife medicine and does this as well. 

After learning the value of holistic medicine first-hand after some injuries, she uses homeopathy, Chinese herbal medicine, acupuncture, Tui Na, and nutritional supplements in her patients. She has lectured about the use of holistic medicine in treating wildlife at conferences around Australia.