"I've never voted before because I've never felt like there was anyone I believed. It's been between bad and worse. (So) I went down to thank her."
Beginning election week in Whanganui Ms Ardern also visited City College, had a lunch at the RSA and visited Q-West boatbuilders.
She addressed the crowd, acknowledging her distant cousin in Whanganui mayor Hamish McDouall and the pharmacy which closed for an hour to attend the public appearance.
"So I'm sorry if you had a prescription to pick up."
Her speech pushed a focus on regional development.
"That is where I'm from so that is the base from where I start."
There were promises to invest more money in regional development, including in roading and locally driven projects.
"We've heard about roads of national significance. Your roads are significant too," she said.
"I commit now that when I'm Prime Minister I will work alongside local government, our local people, to answer the problems that exist in our regions.
"And I can tell you it'll be even easier here because I'll just be catching up with my cuz."
Earlier Ms Ardern told the Chronicle she had been surprised by the huge crowds that has greeted her around the country. "It's been wonderful and heartwarming."
View our photo gallery here:
Image 1 of 9: Jacinda Ardern was in Whanganui on the Labour Party campaign trail. Monday, September 18, 2017 Wanganui Chronicle photograph by Bevan Conley.