Like his niece, he has been selected to compete in the ITU Triathlon World Championships in Auckland over Labour Weekend.
It was Perks who encouraged his niece, born without her right arm below the elbow, to give triathlon a go.
So she did, last year finishing second in both the UK paralympic championships and a Hyde Park race promoting the Olympic triathlon. This month's world championships will be only her third triathlon, yet she wants a medal.
"It will be the best I can give, if that gives me a gold I would be very happy," she said. "I'm not thinking I'm not going to get one [medal]."
Steadman arrived in Rotorua just over a week ago and has already had a few double takes while out training.
"She was out running in the Redwoods the other day and ran past a group of kids and the kids were going to their parents 'she's only got one arm'," said Perks.
"And the parents were like 'sshhh'," laughed Steadman.
Both agree that, in a strange sort of way, Steadman's disability has given her opportunities she may not otherwise have had.
"Sometimes I think just to do a press-up with two arms would be interesting," said Steadman.
"But most of the time I like that sense of being a bit different although I didn't when I was younger."
While here, Perks' coach Sam Warriner is helping Steadman get up to speed with the demands of a triathlon.
Riding a bike with one hand is a skill Steadman is still mastering, especially on the bumpy New Zealand roads.
"The hardest bit for me is the bike, I've always been able to run and swim but because of the arm I have never been that confident [on a bike]," she said. "I've fallen off a couple of times."
In the world championships Steadman will compete in a category specifically for athletes missing an arm and Perks will be her helper at transition.
His job includes helping her get changed, put her prosthetic arm on after the swim and take it off after the cycle.
"We're going to try and get it honed to as quickly as possible as that's where she will lose or gain some time," he said.
All going well, Perks will have competed earlier that day in his 40-44 year age group. Training was going well until he partially dislocated his collar bone in a bike crash in the UK recently.
"At the moment I am touch and go," he said.
Despite the still-strong British accent, he has no qualms about pulling on the black singlet.
"I am proud of it because it's our adopted country now and our trip back to the UK recently made us realise we've made the right move for us in terms of our long term lifestyle."
Steadman too is enjoying Rotorua, especially the roads where she can "just keep going and going" - quite different from her home city of Portsmouth.
With the triathlon to be in the Paralympics for the first time in Rio in 2016, she could have a tough decision ahead of her if the triathlon gig works out.
"If I could do both [triathlon and swimming] I would love to."
