They were on a day's outing to Rotorua after a tough week for Cheng working in Whakatāne Hospital ICU treating burns victims from the Whakaari/White Island eruption.
Cheng, who completed her PhD in nursing in July, was one of the many staff who spent countless hours treating and comforting these patients.
Cheng, in the back seat, died at the scene, her husband Rhys, 49, was left critically injured and two others in the car were seriously injured,
Another adult female passenger suffered broken bones and a punctured lung. She was taken to Waikato Hospital. A 7-year-old girl was taken to Starship Hospital.
The driver of the other vehicle was also seriously injured and taken to Rotorua Hospital.
Due to the impact of the crash, Bugden's stomach was ripped open and his bowel and colon were separated, and he has so far undergone two major surgeries.
His mother Pam Greenhalgh, 74, said unfortunately due to the state of her son's health at the moment her daughter-in-law's funeral had to be postponed.
Greenhalgh said about five days ago, Bugden was transferred to Whakatane Hospital so he could be closer to his family.
"Unfortunately, Rhys was only there a few hours when his condition deteriorated, and he was airlifted to Tauranga Hospital intensive care unit to try and stabilise his condition.
"He is now in a hospital ward and feeling a wee bit better, but it's a day-by-day thing.
"We have been told he will need another operation in about two months times. The doctors' are calling it reconstructive surgery to get his bowel working properly again. "
A tearful Greenhalgh, who has been travelling from Whakatāne to Tauranga Hospital to see her son, said it has been "very tough, emotional time" for him and the whole family.
When Cheng's funeral will be able to be held was unknown.
"It has to wait and see, for now," she said.
Cheng's three brothers and their wives, who were due to arrive in the country on December 20, have decided to postpone their visit, for now, Greenhalgh said.
While Cheng and her son had married later in life in Taiwan four-and-half-years ago, they were "true soulmates".
Greenhalgh said while her son has been talking, he had taken Cheng's death "very hard" and coming to terms with his wife's death would take a "long time".
The coroner has started a formal investigation into the exact cause of the crash, she said.
A Givealittle page set up by a family friend to support Bugden in his recovery and cover his late wife's funeral costs has so far raised $13,585.
