While incarcerated, she was referred to a clinic by the prison doctor where the smear test caught her "high grade abnormality" just in time. "They said if it had been 18 months later then I wouldn't be here."
With a guard by her side, Mrs Harrison-Ratima went to Wellington Women's Hospital for colposcopy, a procedure which revealed the need for surgery - sooner rather than later.
Two months went by and she was released, two weeks later she was on the operating table having extensive abnormal tissue removed.
That was 18 years ago, she's since had a hysterectomy - but Mrs Harrison-Ratima is just happy to be alive and well.
"After the operation, it took six weeks to heal, but I felt that it saved me. I felt that whanau was more important to me, life was more important to me - prison was not part of that - I valued time, to me it was another chance at life."
A misspent youth seems miles away now, with two grown children, a whangai [adopted] daughter, five grandchildren and a set of twins on the way - she couldn't be happier.
Watching her daughter graduate and seeing the kids grow were just two milestones she could have missed out on.
"It's not scary, I encourage ladies to look after themselves," she said.
September is Cervical Screening Awareness Month - aimed at encouraging women to get themselves checked out.
"It's a short and simple procedurethat has a proven ability to save lives," general manager of Well Women and Family Trust Jane Piper says. She recommends screening every three years.
By having regular smears, there was a high chance anything unusual will be detected and treated.
New Zealand has one of the best screening programmes in the world, with the number of women who die from cervical cancer dropping by 60 per cent since 1991.
