The injured woman's mother spoke to the Weekend Herald last night after returning home from visiting her daughter in Waikato Hospital.
She said the 42-year-old was unconscious and heavily sedated, with burns to her legs, buttocks, one hand and a foot.
The woman had read in the local newspaper that police were treating the fire as suspicious, but said she had no idea of the cause.
"I don't know whether he did it, she did it, or whether it was an accident."
She said her daughter had been with the man for several years "on and off".
The Westpac Waikato Air Ambulance transported the injured woman to hospital and a spokesman said her severe burns were thought to have been the result of a petrol fire.
Police would not comment on the cause of the fire, but said they were treating it as suspicious.
Members of the ESR and Fire Safety joined detectives to conduct a scene examination yesterday.
Cordons remained in place around the Taui St house last night and a white tent had been erected in the driveway.
Detective Senior Sergeant Mark Loper said police had spent the morning speaking to neighbours and searching the surrounding environment, including a nearby stream.
A neighbour, Hope Scott, told the Daily Post newspaper she had called the Fire Service after being alerted to the fire by her dog.
She said she could see the burned woman cowering in the corner of a building near the burning home, with skin peeling from her body.
The house was gutted by the fire.
Another neighbour, wishing only to be known as "Kelz", said she was watching television when she heard another neighbour calling for help while she comforted the woman.
Kelz said the pair were on the driveway at the rear of the property when she arrived on the scene.
"She was sitting on the driveway all buckled," she said.
The woman looked like "charcoal" and had burns "pretty much all over her body.
"She was in shock. She was in a bad way ... I was just told to go and get a wet blanket for the lady."
