"But the balance and co-ordination didn't change at all so we thought we should go to the doctor."
Ms Pohatu confessed she tried "Dr Google" and searched for Kemper's symptoms and came to two conclusions - a brain tumour or Freidreich's ataxia.
"It wasn't such a shock for me when the doctor told us," she said.
"I've been training as a nurse and I think that might have helped me prepare a little too. Even when we had to tell him we can't fix it, we were able to tell him all these things we can still do."
Kemper plays rugby for Greerton Marist Gold under-11s and is loving it.
"As soon as he was 5 he was out there playing rugby," Ms Pohatu said.
"That's our biggest goal at the moment, to keep him playing rugby for as long as possible. It will get harder and harder as years go by and we have been trying to prepare him for that."
One of the main side effects of Freidreich's ataxia is a slow degeneration in fine and gross motor skills. This means that some activities may take a little longer for Kemper than other children his age. Ms Pohatu said another side effect was Kemper got very fatigued.
"His fitness, he's really improved. With every hit on the field it takes longer for him to get up but he gives it 200 per cent. He's talking to his coach about it and the families he plays with, they've been told about it."
Ms Pohatu said some families had been incredibly generous and supportive and she wanted to pay particular thanks to them.
"It really makes such a difference. I don't really get to see them on Saturday mornings, because I take Kemper's brother to rugby on the other side of town. But I know they are there and the fact that they want to help, it makes it really special.
"It is going to be a slow progress. We will just have to take every year as it comes."
Kemper is the oldest of three, with brothers Jed and Whairiri and Ziggy the dog keeping the family busy.
As an ambassador for Cure Kids, Kemper will star in the campaign with the All Blacks to raise awareness of the illnesses and health conditions that affect thousands of New Zealand children. The ads will go live on digital platforms in July.
Cure Kids chief executive Frances Benge said she was delighted to have Kemper as an ambassador.
"He is such a bright and outgoing boy and a true inspiration to us all," she said.
Cure Kids is the largest funder of child health research in New Zealand behind the Government.