Taylor has a Facebook page that is managed by a friend who posts updates and messages on behalf of the inmate.
The Herald cannot interview Taylor without express permission from the Department of Corrections, but he is able to pass messages on through the intermediary.
Taylor said his engagement was "great news".
"We're sharing our story, hoping it will give inspiration to others who are yet to find true love," he said.
"It just shows that love can take root anywhere and prevail in the most difficult of circumstances."
Taylor said his bride-to-be was "considerably younger" than him.
She did not want her age published.
"She started following me on Facebook some time ago," Taylor said.
"She was a paralegal in Canada, and a law student, living in British Colombia.
"She started following my cases, then she started sending me some messages which I got and we just started taking quite an interest in each other - more than just friends, shall we say.
"About six or seven months ago we managed to get an international number set up where I could phone Tui on her cellphone in Canada and we started talking.
"It cost me a bit of money actually - we talked sometimes an hour or hour-and-a-half a day and it was great."
Hartman decided to move to New Zealand and see if she could make it work with Taylor.
She arrived on January 3 and met her long-distance love days later.
Taylor said Hartman's father was a Kiwi and her mother was Canadian.
She had lived most of her life in Canada but had spent time in New Zealand before.
She told the Herald she was drawn to Taylor after hearing about him and his work as a self-anointed jailhouse lawyer advocating for prisoners "through the grapevine".
Since making contact with Taylor, Hartman said they had been in contact every day.
"It went from there," she said.
"Then I moved to New Zealand."
Hartman was hopeful that Taylor would be granted parole at this months' hearing.
"I would love for him to be released, nothing would make me happier," she said.