Mrs Fraser's husband Doug told the Queenstown Times yesterday his wife was diagnosed on her 42nd birthday, in March 2010.
"She was in the shower one day and she found a lump.
"She rang me and said she was going in for a check-up.
"I thought she'd be right.
Mrs Fraser was born in Queenstown but moved to Nelson when she was 19, where she met Mr Fraser and married him. The family moved back to the resort in 2006.
The couple have two sons, Alex (18) and Euan (14) both of whom Mrs Fraser was "very proud of", Mr Fraser said.
"[She] was determined to see Alex perform in ... California Dreaming on Friday night."
Mr Fraser said the family had been fortunate to have the support of his wife's "big family" in Arrowtown, along with the wider community during her battle.
"She was always positive and very strong - determined to beat it right to the end and [she] never lost her sense of humour.
"We are all very proud of her."
Mr Fraser encouraged every woman to have regular check-ups, even if there were no signs of abnormalities.
It was thought his wife's lump could have been present for several years before it was detected.
"You need to go and get checked. If she had a check eight or nine years ago ... it may have been a tiny lump and they could have fixed it.
"By that stage [in March 2010] it had spread ... it got into her bones and spread quite rapidly."
He said two girls would be collecting for breast cancer awareness at the funeral today, in the Athenaeum Hall, where people would also be encouraged to wear pink ribbons.
Arrowtown Pink Ribbon Day Street Appeal organiser Julie Hughes Mrs Fraser's death was "gut-wrenchingly hard" for the family, their friends and the wider community.
"We want to make sure women out there think about it and get their checks done.''
Mrs Hughes said seeing the devastation breast cancer and cancer caused to families, friends and communities was heart-breaking.
"For breast cancer to strike down somebody like Karen is hard for the family, her friends and the community.
"It's not fair.
"But, from my angle, if I can save one person's life [by raising money and awareness through Pink Ribbon Day] it's worth it.
"If people come along, support breast cancer awareness, think about it and do a self-check that day, it's worth it."
Following the street appeal today, Dorothy Brown's will screen "Pink Ribbon feature" The Sapphires as a fundraiser.
The Pink Ribbon Day Street Appeal will continue tomorrow, when members of the Arrowtown Volunteer Fire Brigade and the Buckingham Belles will help with the collection.
