It's fair to say that Amphlett lived the lifestyle. Born in industrial Geelong, she left home in her teens and spent time busking in Europe, at one point being imprisoned for three months for singing in the streets; she was born at the right time to be there when punk broke, and her artistic career embodied its values—aggressively forward, unapologetically raunchy and cuttingly honest, expressing both toughness and vulnerability; her voice certainly did.
Amphlett was diagnosed with multiple sclerosis in 2006 and breast cancer in 2010; had it only been one of the two, she'd probably had more of a chance, but apparently the MS made radiotherapy impossible.
There is more coverage, including quotes from other musicians who knew her, here
I imagine it all got subsumed into “new wave”; the Divinyls had that sort of feel about them, probably due to the 1980s zeitgeist; I'd place them alongside, say, the Models rather than AC/DC or Barnesy.
It's interesting that Amphlett was the right age for punk, had a somewhat punk attitude and look, and the Divinyls sounded a bit punk, but they were definitely in the other camp, "Oz rock". The members played in other Oz Rock bands and if you look at their videos you see distinctly non-punk hair, moves and clothes.