"It was horrific. We were mourning. My children from Australia came over to visit me and we started our grieving process."
Her husband Robert was and still is the only person who was told by the surgeon the rough timeframe of how long his wife would live for.
"It really hit home," he said. "I won't tell anyone. That's one man's opinion."
But four days later, she was told there had been a mistake. Her samples had come back she was told she actually had ovarian cancer and all hope was not lost.
"We can never get that time back. It was quite traumatic for all of us going through that process, so we were just speechless when they told us 'oh no, we've got that wrong', she said.
"I've never been so pleased that someone's got something wrong."
"Just the thought process of 'I'm not going to be much longer and how [is my family] going to cope'."
"We hit the ground running; they took me off palliative care and we started with tests, specialists, CT scans, MRIs - you name it, I had it."
She started on chemotherapy and her hair began to fall out.
"I got upset one day because this huge clump fell out but I took control of it myself and we had a 'shave' party.
"I think people see losing your hair and cancer as a bad sign but I saw it as 'no I can take the control back and I can lose my hair when I want to, not when the cancer says it's time'."
Her last treatment was in December and in January it was confirmed there was no evidence of cancer.
Since then, she has welcomed two new grandchildren to the eight she already had, travelled overseas twice, watched one of her daughters get married, celebrated her and her husband's 30th anniversary with a vow renewal and turned 50.
And after a year and a half off work, she returned to Camberley School, where she has been working since 2004.
"It still impacts on me that time and thinking about how technically I shouldn't be here, or I wouldn't be here if they had carried on with that procedure."
They credit their faith as Christians with getting them through this tough time. Not only had Jeffares been battling the ups and downs of cancer, but Robert had been battling demons of his own - depression.
"I was getting better, and off medication, which was really good and this happened and I thought I was going to go downhill again but it actually turned around and made me stronger so in a way I was getting better because of her sickness," he said.
"It was nice to forget about myself and realise someone was worse off than me. It was really nice to be that support."
Now, nine months after coming out the other side, Jeffares has a new lease on life.
"Life is short; go out and enjoy it and don't waste it."
And that's exactly what she is doing. She has ridden 80km as part of a 100km fundraiser, with 90 per cent of funds raised going to the Cancer Society and 10 per cent going to Camberley School.
Having never done anything like this, it all started with "getting fit for the classroom".
"I realised actually I could do something and raise some money."
She will complete her last 20km today at the USO bike ride relay at Twyford School.
"I would give them the world if I could. It is a thankless job - [the Cancer Society] goes over and above for patients just for that comfort to ease your path and your journey that you're on."
She decided to complain about the procedure and an investigation ensued. "We met with a panel and they explained what happened to me."
The DHB have since changed their procedures regarding women who present with certain symptoms of rectal cancer, meaning further screening will be done to check if they have ovarian cancer.
"I hated going through it and I hated having to be that sort of person, but I love the fact they have learnt through this. For me it is about making sure another lady doesn't go through what I went through."
An ACC investigation is also under way after the DHB suggested Jeffares do so.
"I think it could be easy for me to linger on and blame people for what happened. I will never get last year back but I will just use it as a learning curve and be thankful for what I have got."
Hawke's Bay Hospital chief medical and dental officer Dr John Gommans said Jeffares' illness was an "uncommon type of ovarian cancer".
"While the initial diagnosis of the type of cancer was correct, the original site of the cancer was incorrect. This has led to the district health board routinely conducting more testing of women who present with similar symptoms.
"[HBDHB] met with [Jeffares] and her family to explain in more detail the complexity and rarity of her cancer, and to sincerely apologise for the distress and emotions caused by her initial diagnosis and subsequent diagnosis that changed her treatment plan within a short space of time."
He said it was "important to point out that all procedures, scans and lab processes were performed and analysed correctly at all times. There was no misdiagnosis of scan results or specimens in this case."
For more information and to donate, visit: https://give.everydayhero.com/nz/killarney-my-journey-back
For those who want to support and participate at the USO bike ride relay event today from 9am to 3pm, visit: http://www.usobikeride.co.nz/uso-bike-ride-relay.html