A 51-year-old mother of three has become the first woman to run across central Australia's Simpson Desert.

Jane Trumper from Sydney left the Northern Territory 11 days ago and reached Birdsville in Queensland's far south-west yesterday afternoon, covering 660 kilometres.

She ran from the NT, into the South Australian outback and then into Queensland as part of a fundraising effort for the Westmead Children's Hospital charity Bear Cottage.

Ms Trumper says the desert heat was difficult and presented her with a huge mental challenge.

"No female has ever done it, so I think that was in the back of my mind that it would be good to do something that no-one has ever done," she said.

"The biggest difference with this one was the relentless heat.

"It was 45 degrees on the first day and I really had doubts about whether I would absolutely get this thing done."

She said her body held up well.

"It was the heat, the flies and the last couple of days I had a headwind, so the running was very, very slow," she said.

"I actually feel fantastic. I am a bit croaky, with all the dust from the last couple of days, with the wind.

"My calves are tight, there's a couple of blisters on my feet - but pretty good really. I am pretty happy with how it has all gone."