"She had an effervescent personality and zest for life," he said. "She loved life and had a huge sense of adventure."
Mr Collins said his English-born wife first came to New Zealand in 1999 for a 12-month overseas experience.
"After two or three months she met me and that was it," he laughed.
They returned to England for a couple of years before deciding to settle back in Rotorua.
"She loved it [Rotorua] so much ... she loved the Redwoods - mountain biking, walking, taking Poppy for a run," he said, adding she even acquired a slight Kiwi accent.
The adventurous couple had travelled the world together, with Thailand and the Coromandel being two of his wife's favourite spots.
"I'm beside myself with grief but I don't have regrets," he said. "We packed so much into the 14 years we had together, I couldn't have asked for more."
Mrs Collins was first diagnosed with bowel cancer in January 2011 and underwent six months of chemotherapy.
"We thought we'd got away with it. For about a year or so we lived life as if it never happened," said Mr Collins.
"Then it came roaring back in August last year."
He said she put up an intense fight and kept teaching until the end of last year.
Telling their daughter of her mother's passing had been gut-wrenching, he said.
"It's an incredible loss, she's completely irreplaceable, but Poppy and I will soldier on."
Mrs Collins' fellow assistant principal at Lynmore Primary School, Ryves Hunt, said his colleague and close friend's death had "rocked the foundations" of the school.
"She was so young and had so much to offer. She was doing so much for so many people," he said. "Everyone describes her as a people's person, she was always thinking of others."
He said the "always smiling" Mrs Collins had been responsible for the junior school so had got to know most of the students in her time there.
Mr Hunt said staff were struggling with a huge sense of loss, reflected in the outpouring of support from the community.
Mrs Collins' funeral will be held at the Redwoods at 12.30pm on Monday. Lynmore Primary School will close for the day at 11.45am.
Mrs Collins' parents and sister have travelled from England for the service, which Mr Collins hopes will be a celebration of his wife's life.
To that end, mourners are invited to wear bright colours.