She became a role model for working mothers around the world, many of whom saw her as a counterpoint to U.S. President Donald Trump.
She had been in office barely 18 months when a white supremacist gunman opened fire in two Christchurch mosques during Friday prayers, killing 51 and injuring another 40 on March 15 past year.
With New Zealand having the advantage of being an isolated island nation, the strategy worked. The government's decision to close its worldwide borders to foreign nationals in March, and a series of strict domestic lockdowns appear to have been well received by voters, although the virus has pushed the nation into recession.
A Bloomberg report even said that there is a chance Labour could win an outright majority, which no party in New Zealand has done since the 1990s. "It isn't a mania, it's respect", Hayward said.
Ardern reflected on large changes made by Helen Clark's government - particularly in education and welfare - that were still part of the system now, saying they prove smaller changes can become large over time.
One question will be whether Labour can win enough support to govern alone, something that's not happened in the years since the proportional voting system was implemented.
More than 1.5 million people have already voted.
The latest polls cited by NewsHub have Ardern's Labor Party with 47 percent approval compared to 32 percent for National, with a few other contenders languishing in single digits.
The closely watched 1News-Colmar Brunton poll showed support for Ms Ardern's party slipped to 46 per cent from the previous poll on October 8.
Labour has a comfortable double-digit lead over the main opposition centre-right National Party, while support for the Greens has been steady.
"If you want pace and speed, give us a strong mandate", Ardern, 40, said in an interview on Radio New Zealand. Labour has been well ahead in the polls, polling up to 55% to 60% but that's declining steadily.
Other parties which might hold the balance of power, such as NZ First, are looking unlikely to make it to parliament.
New Zealanders are also poised to decide on two landmark social issues on Saturday: whether to legalize recreational marijuana and whether to legalize euthanasia.
"New Zealand First voters might be the sort of people who don't necessarily tell pollsters how they are going to vote, so I wouldn't say this is exactly how it's exactly going to play out on election night".
The government is widely seen as falling short of its promises on three key issues which defined Ardern's campaign three years ago - housing affordability, climate change and poverty.
"No global halo is so shabby, or so fraudulent, as that worn by New Zealand Prime Minister, Jacinda Ardern", wrote The Australian's foreign editor Greg Sheridan on Wednesday. She has just about eradicated Covid-19.
Hayward said Ardern was a naturally conservative and cautious leader who tended towards incremental reform.
"New Zealand has maintained an independent foreign policy for over 30 years".
"National believes there is a better way to get our economy back".