Her positioning on Australia's offshore refugee crisis is a break from the tradition of New Zealand Governments saying nothing to offend Australia - except when it directly relates to New Zealanders.
When she first went to Sydney to meet Turnbull, she said no more or less than what a National Prime Minister would have said.
But since then she has determinedly kept the issue alive.
It has not been done in a reckless way, though it was probably a mistake to say in Vietnam that she wanted a "substantive" meeting with Australian PM Malcolm Turnbull about Manus while in Manila.
That has turned the lack of a "substantive meeting" into a snub by Turnbull.
She has not directly criticised Australia over Manus, framing it instead as nagging refrain to want to help.
The Australian Government had several choices: Turnbull could have given Ardern the courtesy of an informal meeting in Manila to talk it through.
That is something he has done on numerous occasions with John Key at previous summits.
Turnbull could have ignored the issue, which it what he appeared to have been doing until now.
Or he could have reacted badly and that is now what has happened.
The Australian Government has leaked against New Zealand by suggesting intelligence reports have picked up "chatter" by people smugglers wanting to go to New Zealand - with the finger of blame pointed at Ardern.
Her comments have supposedly made New Zealand seem like a soft touch.
It suggests a larger country that has been so used to New Zealand singing in unison that when it goes slightly off-script, Canberra it seeks to undermine it.
It also marks out Ardern as a PM who does not plan to be a satellite of Australia, who won't walk on eggshells because they are supposedly "family."
Bill English's criticism that Ardern is putting on a show about an offer she knows Australia will reject would be valid if Australia actually had rejected it and said there is no way it was going to happen.
But that is not the case. There is every indication that it might be taken up after the deal to dispatch some refugees to the US is completed.
Australia could also remember that the offer was made by a National Party Prime Minister partly in a bid to alleviate Australia's load in dealing with a regional problem that could affect any country in the region.
The only thing that has changed is the urgency with which the refugee detention issue needs to be addressed.
One of the most impressive aspects of the trip was how she and David Parker politically managed the TPP issue while in Vietnam.
Two significant events occurred in private sessions attended by ministers and leaders at a time when TPP was at a crucial stage, technically and politically.
First was when Vietnam temporarily put a halt to proceedings.
The second time was when Canada decided not to attend a leaders' meeting, causing a grand finale event to be abandoned.
Ardern and Parker decided to front foot both events. They did not wait for rumour to trickle out. They gathered the New Zealand media and briefed us and essentially broke the news publicly of important developments.
And when the complexities of the revised TPP11 were released, they instructed the experts in Mfat to answer any questions they could about the deal.
Parker made himself available for backgrounder and interviews.
Former Trade Minister Todd McClay took a more open and consultative approach than his predecessor.
The new Government looks as though it will double down on those efforts.
