Thanks, yeah I'm discovering it all now haha. Clearly had my blinders up!

Most te reo speakers today will pronounce it like this, which is pretty close to how you're spelling it out! https://maoridictionary.co.nz/search?idiom=&phrase=&proverb=&loan=&histLoanWords=&keywords=ngaio

But the 'ng' at the start can really vary across the country, with different iwi pronouncing the consonant differently: Lake Wanaka in south island comes from the māori word "wananga" (wisdom), as Ngāti Tahu pronounce the 'ng' more like a "k" than a "n".

I'm a New Zealand ecologist and I thought it was a pretty interesting coincidence that there's an mystery author with the same name as a native tree.

But she's a NZ author! Strange I'd never heard of her, love the genre. Thanks for the tip-off.