Diagnosed in 2011 with an aggressive brain tumour, Ms Seales fought the debilitating illness for years and never considered the right-to-die campaign.
"Not until that Brittany Maynard Facebook thing came up," Ms Seales said in previously unreported comments from an interview with the Weekend Herald.
"A couple of friends said to me, 'You could do something about that,' and I said, 'Yes, I could.' And I think it's right."
Also suffering from brain cancer, Maynard's decision to publicise her death in the United States went viral online last year with millions of people reading her story.
The 29-year-old "changed the optics of the debate", according to Arthur Caplan of the division of medical ethics at New York University, because she was "young, vivacious, attractive ... and a very different kind of person" from the elderly patients who normally seek physician-assisted death.
Sound familiar?
Ms Seales' case has been a lightning rod for the pro- and anti-euthanasia camps, with some lobby groups successfully intervening into the case to have their voice heard, too.
The 42-year-old's case relies on provisions in the Bill of Rights Act enshrining the rights not to be deprived of life or subjected to cruel treatment.
Opposing the bid on behalf of the Crown was Solicitor-General Mike Heron, QC, who told the court the issue was controversial, unethical and not permissible within the law.
"The current law applies to all. Its purpose is to protect the sanctity of life and the vulnerable."
Not that Ms Seales definitely would end her life if successful in court.
"I want the right to choose. That would give me comfort if I knew that was there," she said in March.
"I don't know whether I necessarily would, because I'm certainly not suffering intolerably now ... But things are only going to get worse."
She said she would be proud if her court case prompted wider legislative change. "I'm reasonably confident that I won't be able to see it through to the end. But if I can get it started, that would make me happy."
Faces of euthanasia
Jeffrey Spector
54, United Kingdom.
Diagnosed with cancer and reignited debate of assisted suicide after travelling to Switzerland where he was put into a coma by a doctor last week.
Brittany Maynard
29, United States.
Diagnosed with cancer and decided to end her life "when the time was right". Millions of people read her story when it went viral last year. Moved from California to Oregon to take advantage of right-to-die legislation.
Lecretia Seales
42, New Zealand.
Diagnosed with cancer and seeking permission of the High Court for a doctor to help her die without fear of prosecution.
