She talked about improving education, ending homelessness and better quality housing, telling them that she wanted to be Prime Minister to make New Zealand the "best country in the world to be a child".
Asked what laws were, the kids of Kaeo seemed to know many of the answers already - being Prime Minister let you make laws, such as not drink-driving, no drug dealing and "no pointing guns".
"No smoking," said one of the children, to which Ardern replied: "Technically some people can but we don't think it's good. We definitely want to get rid of it."
Three children were selected to ask questions, with one wanting to know what happened to the two-lane bridge Kaeo had been promised during the 2015 byelection.
Ardern said she would ask transport minister Simon Bridges to come back to Kaeo with an answer.
The policy was announced just north of the township at one of the 10 one-way bridges National promised to replace. NZTA has said work is expected to start on three of the bridges before the end of the year and the Kaeo bridge next year.
The visit was organised by the Labour Party, which rang principal Paul Barker to ask if they could visit.
He welcomed Ardern wearing a bright red jersey, explaining to NZME that it was an Arsenal supporters jersey because you "can't be too political".
Any caution around that seemed to disappear as Barker welcomed Ardern and introducing her as part of "the change in the country that seems to be coming".
"I urge you four folk over there to remember the things that have made this country a great place to live."
He said it was time to "return to some of those things" and "each of these kids deserves to grow up in the country we grew up in".
"We trust that if the change comes, you will do your best for us."
