She has had to form a coalition government, bringing together two other parties, and has set that Government on course to achieve major reforms in hitherto neglected areas - affordable housing, mental health and child poverty, among others, and she took this on while at the same time giving birth to her first-born - an experience that by itself tests the mettle and absorbs all the time of most first-time mothers.
Not content with focusing on domestic issues, she has also undertaken extensive overseas commitments, representing New Zealand to general acclaim at the United Nations and at gatherings like Davos, leading discussions with world authorities and making important contributions on issues like climate change and mental health.
Then came New Zealand's "darkest day" in Christchurch, and the world marvelled at her capacity to respond to the victims and their communities with love and compassion - to heal a bleeding country, but at the same time to take decisive action on the things that demanded attention - better gun control, more responsibility to be shown by the social media, an inquiry as to whether our intelligence services had done their job properly.
Did the self-styled spokesperson for the "gun lobby", who described her as "dumb as a plank", realise when he appeared on television a day or two ago with that remark what a plonker he made himself seem?
Our Prime Minister is now seen as a world leader. She is a fresh voice, that is listened to with respect and attention. She is seen to embody the virtues of youth and femininity. She has forced us all to reconsider what qualities we can legitimately expect from our leaders. New Zealand's standing in the world has been enormously enhanced. The country's image, reflecting the persona of our Prime Minister, has achieved a new definition in the world's eyes.
So, when the Prime Minister was welcomed in Beijing, it came as no surprise that she was not treated as a supplicant, but as an equal. New Zealand may be a minnow by comparison with the new superpower, but she was recognised as a leader whose message had to be heard. New Zealand is immeasurably advantaged by that kind of stature.
It is an essential part of a constructive relationship with China that, as the Chinese President said, we should "trust each other". The Chinese know that, in Jacinda Ardern, they have a friend they can trust - but also a friend who is ready to stand up for what, on issues like human rights, she knows to be right - as she was ready to stand up to Donald Trump over the threat posed by "white supremacists" and the need to show love and compassion to our Muslim communities. More power to her elbow!
- Bryan Gould is an ex-British MP and Waikato University vice-chancellor.