And with Benji on the scene the support of her husband has become a critical part of her race day success.
That's something she has in common with every running parent, beginner to elite. Getting out the door can relies on the help of the other half with child wrangling. It's a crucial but often under-appreciated job.
Crawford came to triathlon with a background in swimming having competed at national level. Originally racing triathlons as a way to keep fit she quickly realised she was talented enough to take it further.
In 2006 she chucked in her job teaching maths and went pro, keeping a part-time job as a violinist for the Christchurch Symphony Orchestra.
Having raced for more than five years, pregnancy was time to take a break and rejuvenate herself.
In the past, having children was the death knell for the careers of women athletes, but more recently athletes like British marathon runner Paul Radcliffe have shown it is possible to stay competitive and have a family.
Radcliffe famously won the New York marathon 10 months after the birth of her daughter in 2007.
Ironman athletes hit their peak in their mid-thirties, so at 31 Crawford potentially has another five or more years of racing in her.
During her pregnancy Crawford ran until she was 16-weeks along, then walked every day and kept swimming and cycling on a stationary trainer a couple of times a week.
"It felt good doing what I was doing and I never pushed myself harder than what I could do."
She recovered quickly from a two-day labour and emergency caesarean to start back lightly training at the six-week mark.
This is where she made her rather amateur running mistake.
"Definitely don't do what I did," she said.
Stepping out for her first run Crawford planned to go for a pleasant five minute trot. Once running she felt so good she kept going for a whole hour. Ignoring her aching muscles, she headed out again the next day for a 45 minute run. This carried on for two weeks until she injured herself and needed a two week break to recover. Years of running counted for nothing and Crawford was just like any other beginner runner. She dropped back to running for five minutes, gradually increasing her time spent running by a minute at a time.
"I actually felt fit, really fit, but obviously my muscles weren't anything like they had been so they couldn't cope with what I wanted to do."
She now averages around 20 hours of training a week, with a couple of longer weeks in the build-up to an Ironman event. This is far fewer the 30 to 35 hours she was doing before Benji was born.
Juggling motherhood with endurance training sessions has focussed Crawford's approach to training. Anything unimportant has been culled.
Crawford has continued to breastfeed Benji throughout her race build-up, which means training around his sleep and feed times. On her long training days, when she needs to put in seven hours solid, she stops by home for feeds before heading straight back out again.
Despite being warned off running while still breastfeeding by her midwife and finding very little information for mums wanting to train seriously Crawford has had no problems keeping pace with a growing baby.
In fact baby Benji has consistently been at the top of the Plunket growth chart and looks set to crack walking well before his first birthday.
Now based in Whanganui, away from their Christchurch-based family, husband Brett is a crucial part of keeping her on track.
As well as managing all her equipment and support during race weeks, he becomes the main caregiver when Crawford is deep in training.
"So although I am the one doing the racing we are a team and I could never do it without his support," she said.
This week the Crawford household set up temporary camp in Taupo as she seeks a second win at Ironman New Zealand on Saturday. It is the first race in a campaign that will see her race again three weeks later in Melbourne and spend two months in Europe racing mid-year in a bid to qualify for a place at the Ironman World Championships in Kona, Hawaii in October.
A race favourite in what is tipped to be a tight finish, Crawford's competitors know she will be one tough mother.
Events:
* Not content with running a marathon, these guys are swimming nearly 4km and cycling 180km beforehand: Ironman New Zealand, Saturday March 3, Taupo.
