She's been a complete event junkie since and has lost 35.2kg since 2014.
After finishing the Tarawera 50km in November, she knew she made the right choice to enter the Ultra.
"In October, it dawned on me that I would not feel like I was complete unless I had totally pushed the barriers - so I entered the Ultra.
Her extra fitness means not only is she more active, so are her children - Kane, 10, Hayley, 8, Lincoln, 6, Seth, 4, and Mia, 2.
"Now the kids have started to enjoy things like athletics and [Hayley] has shown a real liking for triathlons, so it's put the emphasis on us as a little family.
"I find I have more energy, more up and go to go and do things with them, rather than sit around and do nothing at home."
At one stage she saw the 100km as being "about as challenging as you can get" but has now decided her next goal is the Rotorua Half Ironman and, if that goes well, the Taupo Ironman in 2018.
Being self-employed means Ms Driver can juggle her training and work schedules, run while the children are at school and when she gets chance at the weekend.
"Mum [Teresa Scally] is a big help too," she said.
Ms Driver has set herself the goal of finishing within 16 hours, hoping that being fitter than she was when she tackled the 50km race and having a better idea what to expect will work in her favour.
She is raising money for One Last Cuddle, a fundraising initiative to raise money to create a bereavement room at Rotorua Hospital. Her givealittle page is
https://givealittle.co.nz/fundraiser/100km4onelastcuddle. Follow the results of the race at rotoruadailypost.co.nz.