Aitken, now based in Wellington, headlines the elite field in the fifth edition of the race.
Her record - winner in 2016 and second three times - is an imposing one.
However, she is unsure how she will go.
Having moved north from the West Coast, she has taken up a new role as the national manager for safer people. That has left her to balance a return to city life, family time and training.
"I haven't raced as much this year due to work commitments, so I had my last full-distance race back in July on the Gold Coast," Aitken said.
"Training has been going well so Saturday will be a bit of a surprise as to how I fare.
"I'm excited about lining up and obviously aiming to run as best I can, so what will be will be."
Despite that, the marathon is a significant one for Aitken and there was no doubt whether she was going to return south to contest it.
"This will be year five for me. I have not missed a race.
"Queenstown is a special place for me, having spent much of my childhood holidays hanging out in Central Otago.
"The atmosphere of this event is awesome, from the start line at Millbrook to the cheers and support crossing the finish line.
"It's one I just have to come back for."
Among her toughest competitors would be Hannah Oldroyd, who won last year's race and finished third at the Auckland marathon.
Aitken's husband Steve would also be in action, running the half-marathon.
The event has become hugely popular and is sold out. It has attracted 11,062 entrants across the full and half marathons, as well as the 10km race.
The only spaces remaining are in the children's race.
The majority of entrants are from New Zealand. However, 1339 Australians will run in the event.
There are also sizeable groups from the United States, China and Singapore.
The races begin between 7.45am and 8.30am and will finish at the Queenstown Recreation Ground. A prizegiving will be held at 3.30pm.
