"Looking back, in terms of my smoking, I know it all contributed to my children's asthma and breathing problems so there is definitely guilt there," she said.
"I find I have a bit more breath now. I notice the smell on other smokers too and I can't believe how strong it is. I'm like 'oh my God' I was smelling like that and holding my baby?"
The smoking challenge involved a co-ordinated team effort where people who quit smoking were offered smoking cessation support and advice, including breath-testing checks with a 'smokelyser' machine and other incentives. A colleague encouraged her to enrol.
"I wanted to quit for three reasons " for my whanau, for my finances and for my health. Life is too short," she said.
Looking back, Ms Nathan said she took up smoking because everyone around her, including close family members, smoked which she viewed as a typical thing to do.
She is feeling proud of herself now and gets to spend more time with her children.
Ms Nathan said she no longer has to say 'get out of my smoke' or 'I won't be long, just give me a minute' to her family.
Once the 10 per cent tax on tobacco per year is in place, a pack of 20 cigarettes will cost about $30, one of the highest prices in the world.
The increase is part of measures designed to make New Zealand smoke-free by 2025. On average, a smoker spends $2800 a year on cigarettes.