It has been a juggle for the remarkable Crawford, who was a former competitive swimmer as a teen but discovered triathlon less than 10 years ago. Her training regimes have to be fitted around the needs of her son.
"My emphasis is on quantity not quality," she said. "I have to be very flexible with my training as I am still breastfeeding.
"I always felt that I was just trying to keep up with what others were doing. I knew everyone else was doing 30 to 35 hours a week training so I thought that's what I had to do.
"Now, I'm doing all the crucial sessions but have cut out any recovery sessions and it's working a lot better. I'm a lot fresher because I'm not so tired all the time and when I do a sprint session I feel I can go a lot faster.
"Once I set my mind to something, I'm pretty determined. In Ironman it helps to be determined and the mental side is just as big as the physical side."
Jacobs was a former member of the US armed forces and turned to triathlon after the birth of her daughter. She had nearly seven years in the army serving in Korea, Germany, Virginia, Kentucky and Texas.
She has a running background, with a best time in the marathon last year of 2:48, and she is looking at the qualifying mark of 2:45 for the US Olympic trials.
Jacobs had her first success with a second placing at the US duathlon championships and turned professional in 2007.
The 33-year-old was sixth in Ironman Canada in 2010 before a breakthrough victory in Florida that year. Last year she stepped it up with some solid 70.3 (half ironman) results before victory on her home turf at Ironman Wisconsin followed by a successful defence of her Florida crown. She completed the Florida course in a remarkable 8:55, the 13th fastest ironman time in history by a female, on the back of a 2:53 marathon, which was the fastest ever by an American.
It's her first time venturing to this part of the world, as she looks to compete in both Ironman New Zealand and three weeks later in Ironman Australia.
The seedings for the women's race at Ironman New Zealand are: 1: Joanna Lawn (NZL), 2: Gina Crawford (NZL), 3: Jessica Jacobs (USA), 4: (Meredith Kessler (USA), 5: Kate Bevilaqua (AUS), 6: Belinda Harper (NZL), 7: Candice Hammond (NZL), 8: Rachael Paxton (AUS).