"We'd had another classmate die suddenly about 25 years ago. With those two deaths, we thought it was a good idea to have a reunion before anything else happened."
So Ms McCulloch and Ms Potaka took to the internet to track down their old friends.
"One woman had just moved back to Wanganui after 27 years in Australia, and a week after she arrived she got an email from me telling her about the reunion."
Most were still living in Wanganui, but others came from Feilding and Napier, and as far away as Brisbane, Ms Potaka said.
"But it was like we'd never been apart - we were so comfortable with each other. It was a hilarious weekend, lots of talking and laughter."
She said it was interesting to note that all the women had "done really well for themselves" and quite a few had their own businesses.
A surprise came during lunch at the Avoca when their form teacher, 86-year-old Edwina Dove, arrived to join the festivities.
"We hadn't told anyone she was coming," Ms Potaka said. "We'd all been talking about her, and it was just great to see her again."
Now that the group has reunited, there are plans to keep the revived friendships going.