"I had a turn and it was, 'Oh, my god'. It was really cool. They weren't as graphic as they are now - they are much more colourful now and the music really draws you in. But it was such a buzz getting the free spins and then stopping the counter on the 12, rather than the one, which said how many free spins you got.
"I never did cards again. All I wanted was the pokies. I would go anywhere that had pokies and I would blow a lot. I could easily blow a thousand in a day."
That was in 1991. Herbert, now 49, spent the next 20 years in the grip of an addiction to the pokies. She reckons she "did $40,000 easily" in that time, by pawning and selling anything she could get away with, or stealing from her partner's bank account.
As problem gamblers go, she verged on the responsible: she always made sure she left enough in her partner's bank account to cover the bills. But she was still hooked.
"It got to the point where I didn't care whether I won or lost," Denise says. "Playing the pokies was my space. When I was there, I could zone out into my own little world. The pokies became my best friend - and my worst enemy."
The turning point came when she rang the Problem Gambling Foundation's 0800 number. In short order, face-to-face counselling was organised, but Denise had another act of self-sabotage in her.
The appointment was for 10am. It was payday, and she had arranged to go to the beach for the weekend with her sister and a bunch of kids and grandkids.
"I went to the pokies and blew everything I had," she said. "My board, the money I was meant to be using to buy groceries to go north, everything. That finally broke me."
Now 19 months "gamble-free", as she calls it, she's studying for a degree in social work. And she is in no doubt that the Government's deal with SkyCity in which the latter will build and fit out a new convention centre in return for permission for an additional 230 poker machines and 40 gaming tables, is a bad idea. "Just don't do it, is the short answer," she says.
"In Whangarei, we are told that the profit on pokies is $15 million a year, and a third of that goes back into the community. The way I see it, we are in a recession and there is a lot of poverty up here. If there were no pokies, we would have 100 per cent of it going into the community."
Denise accepts that many people enjoy a flutter with no ill-effects. "If you can go to the pokies and put a few bucks in on a Saturday night, that's fine. I don't have an issue with that. But if you reduce the number of machines, you will still have that opportunity."
The Government's deal with SkyCity, signed on July 6, first came on the public radar at the same time as cuts in funding for support services for problem gamblers were announced. The Public Service Association suggested in May that the Government should offer a 35-year guarantee to these services to match the extension to SkyCity's licence. There has been no response.
Problem Gambling Foundation helpline: 0800 664 262.