Jacinda Ardern shared a photo of baby Neve, albeit mostly out of view, on Instagram, with her favourite toy.
Neve's hand is holding an old soft toy which Ardern says in the caption used to be hers.
"Amongst a few other options, Neve has settled on this pretty worn and misshapen bear.... the same one I had as a baby," the Prime Minister wrote.
"The benefits of having a Nana who hoards."
Neve's brown bear toy was a hit on Instagram, with nearly 25,000 likes in just a couple of hours.
Social media users approve of the hand-me-down.
"That's a beautiful bear. May she rise to emulate her incredible mother," an Instagram user commented.
"Fantastic bear! Generation to pass to the next in person with love," someone else said.
"Amazing to experience baby's intuitive connection to their past! My daughter loves her daddy's 40-year-old teddy," another person said.
Ardern has mostly kept Neve away from the spotlight her job entails but likes sharing details of her daughter with New Zealanders.
At an Auckland Writers' Festival event on Sunday morning, Ardern said Neve was a big fan of playing with paper.
Cabinet papers often looked dog-eared after some time at home, she told the audience.