The Turakina Māori Girls' College Old Girls Association says the interim decision that the kura should close has come as a surprise.
The kura had been earmarked for possible closure next year after its proprietor, the Presbyterian Church, experienced financial problems and the roll fell to 54.
Minister of Education Hekia Parata said information provided through submissions did not instill her with sufficient confidence in the school's future.
But the former student association's president, Hemaima Eichstaedt, said the announcement was unexpected.
She said the association had provided her with detailed information and strategies outlining ways to keep the kura open in its submission.
"We thought we had enough information in our submissions. We thought we covered every base, everything that she was looking for: recruitment, helping her increase the role as well as providing funding.
"We had a plan of sponsorship to help fund students to go to the school. The only area that we couldn't really touch base on was the safety of the school to help bring it up to standard."
Ms Eichstaedt said it was looking at assisting the school's board of proprietors in getting its buildings up to standard and approaching potential investors.
Rangitikei District Council Mayor Andy Watson is a longtime supporter of the kura.
He said he was disappointed by the decision but was hopeful that the kura could still stay open.
"Originally the minister had said there would be a further consultation period and that has kicked in. On one hand, I'm disappointed that a positive decision wasn't made to keep the school open, but it does provide the school with an opportunity to provide more information.
"My understanding is that there are a number of avenues of discussion from the Old Girls Association and possible financial sources, which would take time to be able to be presented to the minister."
The school's board of proprietors and board of trustees will meet this week to discuss the minister's announcement.