"It was the odd puff then I started being sneaky," she said.
Her habit lasted 22 years and she didn't even quit during her two pregnancies - just cut down.
"My partner at the time told me I needed to but because he was telling me to quit, I didn't."
She believed boredom and habit were the two major reasons she kept puffing away.
Living on a farm with the children, she'd often have several ciggies while doing the housework.
Miss McCormack said when she first gave up at the end of 2012, her children were "absolutely rapt".
Knowing how disappointed they'd be that she'd taken it up again, she hid in the garage and smoked, or claimed she was out "feeding the chickens".
Miss McCormack even had a stash of mints and body spray hidden in the garage to disguise it - until one of them caught her.
She said she was hopeful this time she'd quit for good. She said Champix had been useful in helping stop, and she was relishing the better tasting food, nicer-looking nails and not having the cigarette smell hanging around.
Besides, with the habit costing her more than $40 a week, she reckons there are better things to spend the cash on.