The numbers appear to be simply made up out of thin air, so it doesn't matter what the units are.Is that US or NZ dollars?
Yes, but apparently nobody knows how much money she actually made from this.I recall that she is also a successful author.
I did a search on Google for jacinda ardern net worth. There are basically two types of web sites that come up. One is the usual celebrity stats web sites that publish dubious data scraped from Wikipedia or simply made up. The most common number these come up with is $10 million. Their source is "we researched this". In other words they either just made it up or copied it from another celebrity stats web site.
The other type of web site is political opponents of Ardern, including anti-vaxxers. These tend to quote the $25 million figure. If they give a source at all it's from the above Twitter post, who apparently is just pulling the number out of his arse.
The Twitter post which was posted above shows up in a Google search. I won't link it here as I don't want to raise its search profile any further. The posts under that one are all either of the "Ardern is corrupt and must go" flavour, or anti-vaxxer posts, with the latter predominating. I suspect the two are actually related.
I suspect that somewhere on a Telegram group there is a discussion along the lines of "our attempts to discredit the vaccines isn't working, so let's discredit the government ministers who are buying the vaccines instead".