The article notes Ardern's stances on making abortion legal, fighting for equal pay, and her strong reaction when asked on the campaign about whether she had plans to have children.
In an Apec-preview article, The Guardian referred to that reaction as a reason why Ardern was one of five world leaders who could give Trump grief at Apec.
"There are signs that Ardern would not allow a sexist remark from Trump to go undefended," The Guardian article said.
"In August, when asked by a radio host if women should tell their employers if they planned to have children, she responded angrily."
There were no such clashes when Ardern finally met Trump at Apec. They were introduced by Canadian Prime Minister Justin Trudeau, and afterwards Ardern said she did not have a conversation with Trump.
The BBC also quoted Ardern on anxiety, comparing her openness with Cambodian Prime Minister Hun Sen's comments about smashing the opposition and locking up demonstrators.
"I'm constantly anxious about making mistakes. Everything is politics feels so fragile," Ardern told Next magazine earlier this year, before she became party leader.
The BBC also compared Ardern's gay-friendly views to the fact that same-sex marriage is still illegal in more than half of the Apec countries. Ardern has cited LGBT issues as one of the main reasons she left the Mormon Church.
On climate change, The BBC contrasted her with US President Donald Trump, who has withdrawn the US from the Paris Agreement. Ardern has called climate change her generation's nuclear-free challenge, and committed to net zero emissions by 2050.
But it also noted that The Wall Street Journal likened Ardern to Trump for her stance on immigration.
"Ms Ardern is not going to build a wall and she has not supported a travel ban like Trump, but she does want to cut annual net migration by up to 30,000 people a year," the article says.
"So, liberal, casual and the newest leader in the Apec pack Ms Ardern is now part of a select group of women in power - but will she leave the summit with more friends or foes?"