Smith said the side had a hard look at their performance and got straight to work.
"When we played them in June, their forward pack really dominated us. So we went away and went back to our fulltime jobs," she said.
"Not only that, every moment of spare time we had we'd get together and we'd go through some of our forwards stuff so it wouldn't happen again.
"It looks like it paid off, fitting all those extra sessions around our jobs."
Since only the sevens players are contracted by New Zealand Rugby, the majority of the squad have fulltime jobs outside of their rugby commitments.
Smith is a police officer and said her work had been really good with allowing her to chase the trophy.
"They've been awesome, really supportive of me," she said.
"I've been getting video messages from my section and from other police from around New Zealand which is pretty cool.
"I work shift work so night shifts and everything. Fitting training and everything around it is tough but we make it work."
The win gave New Zealand their fifth women's world title and marked the first time New Zealand had held the men's, women's and under-20's World Cups.
Smith said while the successful campaign was something to be cherished, there was a lot more to enjoy about their time in Ireland.
"All the support we got from home and the culture that the Black Ferns and New Zealand Rugby have was great," she said.
"That's been developed from players from before I even knew what rugby even was.
"It's been really awesome having support, not only from New Zealand but from around the world.
"And just seeing women's rugby grow and having little girls want to play rugby as their sport of choice. It's pretty cool I reckon."