"We wanted a Maori name for him."
Ms Hanham found out she was pregnant in May last year and started hunting for a name as soon as she found out she was having a boy.
It was only about a month before she gave birth that the couple decided on the name Nikau.
When he was born on January 22 - four days before his due date - they knew they'd made the right decision.
"He was perfect. I'd been trying to imagine what he'd look like and what he'd be like. It's very special when you first get to meet him."
Ms Hanham kept Nikau's placenta and is going to plant it underneath a nikau tree.
She said her son is a good baby who is always happy.
"He's really chill, he's always smiling. It's very rarely that he's crying. He's got a real personality now he's just started copying and laughing."
Nikau is Ms Hanham's first baby but Mr Keefe has a 5-year-old son called Tane - the 20th most popular Maori baby name - who loves his new little brother.
"Nikau looks like his brother. A lot of the facials he pulls he looks like Tane," Ms Hanham said.
The most popular Maori name for girls in 2016 was Maia. Other names on the list include Ariana, Anahera, Manaia, Ari and Te Ariki.