Jaxon was delivered nine weeks early and stayed in hospital for 112 days - but had to be evacuated for a short time when the February 22 earthquake struck in 2011.
Now he is a thriving little boy, said Robyn.
"He loves reading, he just loves knowledge, so I think he will do well [at school]," Robyn told the Herald on Sunday.
"He is happy. He likes playing outside and playing with water. He has been doing a couple of years of swimming, which has helped his physical development."
Jaxon has four more sleeps until his 5th birthday, but he will have to wait until next year to start school.
At age 3 it was discovered he had microcephaly, which is a neurodevelopmental disorder where the head is smaller than it should be. Jaxon's condition has limited his physical development, motor skills and social skills.
Despite the ongoing setbacks doctors were "impressed" with what Jaxon could do, Robyn said.
But getting Jaxon to this point had not been an easy ride. "He finds social situations quite hard, just the sharing and turn-taking.
"We also found out he gets bad migraines.
"He can't go outside and he can't walk so he ends up being inside for a few days."
Bellve said early intervention and good nutrition was starting to "pay off" and they had high hopes for their boy's future. "We are trying to decide on schools now and see what help he will get at school, if any.
"That will determine when we can go and how long he will be able to stay there," she said.
