Crawford (31) won the Challenge Wanaka race for three consecutive years before taking a year off in 2011, when she was pregnant with her first child.
She holds the women's course record of 9hr 28min 27sec, which she set in 2009. Her goal tomorrow is to break that record and regain the women's title for a fourth time.
Her son Benji will be at the forefront of her mind during tomorrow's gruelling race.
"The hardest thing for me on race day would be probably not feeding my baby," Crawford said at a Challenge Wanaka media conference yesterday.
Despite attempts by Crawford and her husband Brett to wean their baby, "he had none of that".
Crawford told the Otago Daily Times Benji usually fed every four or five hours, so it was "a real unknown" how that would impact on her performance.
"Obviously it will be quite painful for me by the end of the race."
Crawford gave birth in mid-July and resumed structured training by September. The last major race she competed in was the Ironman Wisconsin in September 2010.
Her training for Challenge Wanaka had been "going well", although "a lot differently" since Benji was born.
"I train around Benji's schedule and he doesn't really stick to a schedule. I have to be really flexible."
She has reduced her pre-pregnancy training time - between 30 to 35 hours per week, to just 20 hours a week.
"It's more about quality, then quantity," Crawford said.
"I've cut out all the fluff, so I've just focused on the crucial sessions ... every time I go out, I've got a real aim of what I want to achieve."
However, the less regimented approach was proving to be a positive one.
"When I do train, I do feel a lot better and a lot faster than I was.
"I feel fresher and I feel more sharp."
Most recently, Crawford achieved personal bests at the Taupo Half Ironman and the Olympic distance Tauranga Tinman race in December.
"I raced faster than I was pre-pregnancy so that was a good gauge of how I'm going and I just want to carry on with the iron distance now."
She was thrilled to be back in Wanaka, where she had enjoyed so much success in the past.
"I think it's a beautiful place. It's the most beautiful in New Zealand. I just love coming here and the amount of tracks they've got is amazing, not just the one we run on ... It would be awesome to live here and train on those tracks all the time."