"She was in the car for about 20 minutes and, by the time the paramedics got to her, she was fitting. They don't know how long she'd lost oxygen to the brain," she said. "The best-case scenario is some brain damage, but we don't know how bad, which might affect the right side of her movement. She can't move her right side at the moment."
Her father, Craig, took the first flight he could get to Melbourne after hearing the news on Sunday and spent yesterday sitting by Miss Wilson's bed holding her hand.
In a Facebook message, he told friends and family his daughter's future was uncertain. "Diane is very unwell, but as you'd imagine, battling hard ... we still have a couple of days before knowing if Diane will actually survive this horror and begin the long road to recovery. If she does she will almost certainly have some degree of permanent inability to move the right side of her body due to brain trauma."
Mother Susie Wilson, brother Michael and sister Bianca, who all live in Australia, were also by her side.
Kathryn Wilson said her stepdaughter's spinal cord had not been damaged and the family was hoping she would come through with no major lasting effects.
"When Craig was talking to her, when he was holding her left hand, and was telling her we just want her to get better she squeezed his hand. That's really positive," she said.
"She's come through so many operations in her life, one of them was a 13-hour surgery. To come through all that and be hit by a drunk driver is heartbreaking. Just incomprehensible."
Miss Wilson had been given a promotion at work a week ago.
"She was made full-time supervisor of a cleaning team for the hotel chain. The last phone call Craig had with her, he was telling her how proud he was so that's pretty special," she said.
Can you help?
A fundraising page has been set up to help the family with costs involved in Diane Wilson's recovery. $585 has been raised so far.
www.givealittle.co.nz/cause/Wilsonfamily
