And she knew exactly where to find the box.
"I told staff member Helen Roderick it was in a cupboard on the left-hand side in the library," she said. "No one was aware it was there, and it's a pretty brilliant and amazing collection of the pupils' work."
Mrs Edwards said she knew about the third-formers' work because her father, a World War I veteran, had been interviewed for the project.
"There are plenty of other World War I memories in that box and it's a special historic find," she said. "I have one photo of my dad, T J Sherrard of Pongaroa, with his kitbag, heading to Wellington. To think, those third formers had compiled a wonderful book of stories and recollections, researching without the aid of Google, all spearheaded by their teacher - just stunning."
The pupils, all top third-formers, had no computers to collate their hundreds of pages of work. Instead, it is all laboriously handwritten or tapped out on old typewriters.
"I'm absolutely fascinated by the work the pupils did and I hope a copy goes into our Gallery of History," Mrs Edwards said.
The pupils' explanation of the reason for their work is attached to a class photo.
"All 31 of us in this class have family members or friends who served our country in the world wars. We have all participated in this investigation of the effects of the two world wars on our community," they wrote.
John Hart, president of the Dannevirke RSA, said the find was very significant, especially as we begin to commemorate 100 years since the start of World War I.
"I'm overwhelmed by what this box contains, it's unbelievable," he said. "It's magic and it's all local connections. To unearth this treasure this year is special."
For Mrs Roderick, the find also has special significance - her son Simon did all the intricate artwork for the project in 1989.
"I guess he missed a whole term of social studies to complete the work but it's very special," she said.
Included in the archive is a taped interview with the then 91-year-old World War I veteran Wally Scott. However, no one has yet listened to the tape, which will be copied to a compact disc that the RSA will pay for. "Our kids love this stuff. It's incredible," Mrs Roderick said. "The work those former pupils put into this is absolutely fabulous."
Dannevirke High School principal Dawid de Villiers said pupils were asking how their former peers could have brought together such a collection without the use of computers. "They're in awe," he said. "This is a really special piece of local history."
Dr de Villiers said his dream was for the high school to have a home to keep all its important archives together.
"I'd like to see the upstairs of the old boarding house, MacDonald House, done up to accommodate our archives," he said. One mystery remains - the whereabouts of a special medal presented to the class of 1989 for winning the RSA competition 25 years ago.
