"We were starting to get really confident she was going to win this battle."
But last weekend the almost two-and-a-half-year-old kiwi suddenly deteriorated due to a suspected brain bleed or stroke and the decision to euthanise her was made.
She has been sent back to the Wildbase Hospital for a necropsy.
"Hopefully some learning will come out of it, there's so much we don't know about these creatures," Fry said.
Kiwi North posted the sad news on its Facebook page.
"Our big, feisty, girl who loved to have her own way could not boss her way out of this battle."
Messages of love and support have flooded in from locals and people from around the world who had visited Kiwi North on their travels.
Jockalene and Ben arrived at Kiwi North in 2017 when they were around 10 months old.
Fry said Kiwi North's "link in the chain" of the captive breeding programme is to raise the teenagers "and while we've got them, we use them for education and advocacy for the species".
The environment for the kiwi is as natural and hands-off is possible.
Jockalene and Ben were both set for release to a sanctuary in the next few months.
When Ben goes, Kiwi North will receive two new kiwi.
Fry said Jockalene was part of the team at Kiwi North and losing her was incredibly upsetting for the staff.
"It's sad when they go either to the breeding programme or a sanctuary but when we lose one like this it's heartbreaking."
Fry said they euthanised a kiwi about five or six years ago after it developed a growth in its uterus.
