"We know it's going to be war. We're just going to give them everything we've got.
"And God, it would be good to beat the Aussies. I've still got that Kiwi desire to beat them at any moment."
Painter-Snell came up the water polo ranks at Epsom Girls' Grammar School and the Marist club, and was in the New Zealand side for the junior world championships in 2007.
After a stint playing professionally in France, she moved to London, and has been in the British team since 2009.
Although the New Zealand women's team had no realistic chance of making the Olympics, she said the decision to change allegiance was agonising.
"I remember at the time it being really, really difficult. But when I look back now, I think, what was I thinking - why did I ever doubt it?"
She said the Olympics have provided some memorable moments.
"I met Princess Anne the other day, and I was trying my best to put on an English accent.
"But I've been here five years and I still have my Kiwi twang - I don't think it's ever going to go away."
And with her family over from Auckland and hundreds of best wishes from friends in New Zealand, she says she has home and away support.
"At the moment I'm 99 per cent British because I've got to be supporting the whole of Team GB.
"But I've got my pounamu that one of my Maori friend's family gave me for my 21st, and I wore that to the opening ceremony to have my little piece of Kiwi strength with me."
