Tamra McBeath-Riley, 52, is being treated in hospital for dehydration and exposure after she was discovered late on Sunday.
Rescuers are using helicopters to search for her two companions – Claire Hockridge and Phu Tran – who were last seen on 19 November.
The trio had left Alice Springs for an afternoon drive, but their car became bogged in a riverbed.
According to ABC News, they stayed by the car for three days – relying on a supply of six litres of water, 10 cans of iced vodka, a packet of biscuits and some beef noodles.
With temperatures reaching up to 40C (104F), they dug a hole underneath the car in an attempt to stay cool during the day – and slept in the car at night.
When supplies ran out, they made the difficult decision to move on.
They left a note on the car and found a watering hole about a mile away. Ms McBeath-Riley decided to stay here with her Staffordshire terrier, fearful that the dog wouldn’t survive a longer trek.
Her two friends began a 12-mile trek towards a highway, armed with a GPS device and a compass.
The pair had planned to avoid the desert heat by walking at night. Although they were carrying six litres of water to stay hydrated, they had little in the way of food.
Ms McBeath-Riley has been coming to terms with the news that her partner Claire and their friend Phu haven’t been found yet.
She told reporters: “When the helicopter found me, I thought that Claire and Phu had reached the highway. That was my immediate thought. So to find that’s not the case is worrying.
“I’m sure he won’t want to go four-wheel driving with us ever again.”
A cattle rancher played a crucial role in saving her – he called the police when he spotted tyre tracks in an area that was yet to be searched.
Rescuers are continuing to look for her two friends, but Police Superintendent Pauline Vicary said only one set of footprints has been found so far.
She added: “It’s quite a diverse terrain. There’s sandy dunes, there’s hard clay, there’s areas of dense trees, but there are also rocks and ranges in the area.”