The surgery, to be carried out in Melbourne's Alfred Hospital, was expected to take up to four hours.
Miss Wilson, 23, sustained a smashed pelvis, broken neck at the base of her skull and brain bleeds and was in an induced coma after the car she was driving was T-boned. The crash happened on the corner of Through Rd and Toorak Rd about 2.10am on Sunday (Australia time).
The surgery to be carried out last night aimed to reattach the base of her skull to her spine and would leave her with permanent restricted movement of her head. The top bones of her spine would be fused together in the surgery.
Miss Wilson was born with Crouzon's Syndrome, a condition that meant the bones of her skull were fused together, and had numerous surgeries to reshape her face and head between the ages of 1 and 17. The Bay of Plenty Times published stories and photos about her surgeries.
She remained in an induced coma yesterday and doctors were still not certain she would pull through but the family were holding out hope.
In a Facebook post father Craig Wilson said Miss Wilson's sister asked the doctor if it would be a miracle for her to pull through "his reply was, 'yes. And it is already a miracle she survived the crash".
Mr Wilson yesterday told the Bay of Plenty Times a CT scan on Monday night revealed no new problems and allowed doctors to schedule her surgery.
"She has several clots in her brain and they wanted to make sure it hadn't caused a stroke or anything," Mr Wilson said. "That actually does feel like a positive step.
"It makes us feel like she's going forward even though she's not really.
"Doctors told us last night it hadn't crossed their minds yet not to aggressively treat her."
Miss Wilson's father, mother, brother and sister had been taking it in shifts to stay by her bedside.
"She's pretty lifeless which is really sad when you're there but she is alive, although she's certainly not out of the woods yet," Mr Wilson said.
It would still be some days before doctors knew what the outcome could be but the outpouring of support kept the family strong.
"The well wishing through Facebook, it is tremendously heartening. It does help. She's touched so many hearts in her life and Diane's so positive."
A Givealittle page has been set up to help raise money for Diane
*The initial target was $500
*As of 6pm yesterday more than $4000 has been raised
*To donate visit: www.givealittle.co.nz/cause/Wilsonfamily