"What they've said to me is it's a waiting game, it's every day wait and see," Kelsen told the Herald on Sunday.
"But that's better than when we first arrived - it was, 'Fiona, we'll give you 72 hours and then we'll have a chat about turning life support off'. So things are more positive - way more positive - now."
Kelsen spent about three months in Britain after Harris' 2007 accident and has again had to rush from their Taranaki home to be by his side.
If Harris does recover, Kelsen believed he would attempt another comeback.
The couple, who first met when they were 10 or 11 years old, have been together for 20 years.
"He's a pretty amazing guy, and he's amazingly determined. Nobody saw the behind-the-scenes work he put into getting back to where he is [since 2007] ... It would be so awesome if he could just wake up."