Jacinda Ardern only took over her Labour party leadership 6 weeks before our last general election after the previous leader resigned. Her Labour Party was in opposition (Not in power) and was significantly lagging behind the incumbent National party in polls. 6 weeks later they were elected to government.
As well as everything she has done for New Zealand as leader she is the first leader to have a child while in office since Pakistani prime minister Benazir Bhutto in 1990, and was the first leader ever to bring a baby to a United Nations conference.
Jacinda Ardern and her partner Clarke, NZ's 'First Bloke', are not yet married. Since Jacinda was elected Prime Minister they haven't had time to plan a wedding, so you could say NZ is the only nation in the world being lead by a solo mother, though that would unfairly diminish Clarke's role as a parent.
In good news, the National party has just had their worst poll result since Jacinda took power so hopefully that holds through to the election this August, but then it was a similar situation in reverse before Jacinda took power so who knows.
In New Zealand politics Jacinda's Labour party is left of center on the political spectrum and National is right of center. I would say neither parties viewpoints are skewed far enough to say either is Left-wing or Right-wing in the way the two dominant US parties are, but like the US public political opinions have become much more polarised in New Zealand over the last 4 years. Particularly after Jacinda banned Automatic weapons in the aftermath of the Christchurch terrorist massacre.