In 2006 the Herald on Sunday revealed Miller, 23, had resigned from her job at Tararua College in Pahiatua, in the Wairarapa, after confessing she was in a sexual relationship with her year 12 English student.
She had been gaining the experience required before she could apply to be a registered teacher. Because she was not registered, the Teachers' Council did not investigate.
At the time, Macdonald told the Herald on Sunday of the relationship: "It's awesome. Some of the kids that know you just ignore them. Some of them think it's pretty cool. She was a student teacher ... it was just like a growing interest."
Miller said the relationship had "snowballed" out of control and she did not expect to be ever allowed to teach again, after the affair. At that stage, the pair wouldn't say if they were in love or not. Miller said: "Well, no white picket fences just yet".
Four years later, the Herald on Sunday revealed Miller was back in the classroom, this time at Dannevirke High School up the road, with a provisional teaching registration. The school had employed her as an automotive instructor, then as an English teacher.
Miller and Macdonald at that stage were engaged and had a baby. Macdonald also had plans to become a teacher and was working part-time as a music tutor at Dannevirke High School.
Miller is now a Year 9 dean in pastoral care at the school but did not want to comment for this story.
The couple now live in Feilding with their three children- two girls and a boy.
Macdonald is a year 10 dean at Palmerston North Boys' High.
"We are happy and all that," he told the Herald on Sunday last week.
"Our relationship has lasted the distance, that's all I want to say."
Miller's principal, Di Carter, said she had no idea about the couple's relationship when Macdonald was Miller's pupil.
"I heard something but that was way before my time. We are very happy with Tash, she and Hayden are happily married with three children.
"It makes no difference to me what happened and I would like to say she is a dean and a very respected colleague of our school and community - we support Natasha."