"It gives me a huge amount of empathy for all mums - whether you're a working mum or a stay-at-home mum ... especially if you're a solo mum."
She says her 18-month-old daughter Neve is developing a personality like her father Clarke's, something Arden believes was "inevitable".
"it's one of the things I've found most rewarding about this year is that she's just developed ... she's her own little person. And that's really lovely; you see snippets of who she's going to be, and she's curious and she's funny."
Ardern jokes that her daughter "doesn't need" her - except for food and the occasional nappy changes.
"And even then, she could take it or leave it," she told the Weekly.
She says Neve, already a budding performer, will no doubt play a leading role when her parents get married - though a date still hasn't been set.
"She'll try and play a starring role. She'll make herself known to people - one of her favourite words is 'hi'.
"And if you don't say hi, she just gets louder and louder and louder."
Neve has transformed their home life, says Ardern, noting she has a "whole extra layer" to her world. She also shared that having family members to help out means she has "the chance to enjoy it" too.