Tucker rushed to the house but "there wasn't no way I could get into it."
The family had switched from heating with wood to an electric heater and it was the only heat source in the house, James Tucker said.
Blair said Tucker lived in the home with the children's father, Billy Wilfong. The two weren't married but had been together for about seven years, she said.
Blair identified the children as 5-year-old Dakota Lee; 4-year-old Tyler Lane; 2-year-old Cheyenne and an infant, Emily, who was 6 months old. She said she watched the kids often and said they loved to play outside and watch TV together.
"They were good kids, you couldn't ask for no better," Blair said.
Roberts said the bodies would be taken to the medical examiner's office in Frankfort, and it could take several days for positive identifications. The infant was found within a foot of the father, and all the victims were within about two feet of each other.
"They could've been overcome by that smoke and just went into like a deep sleep," Roberts said. "They just couldn't make it out."
Doug Tackett, Pike County Emergency Services Coordinator, said hot spots still marked the house as of early Wednesday afternoon.
"They haven't even started the recovery yet," Tackett said. "It was a hot one, yes indeed."
No officials could recall a similar deadly blaze in Kentucky since 10 people, including six children, were killed in a house fire in Bardstown in February 2007.
County Judge-Executive spokesman Brandon Roberts said there's been no similar fatal fire in the county in recent years.
"I can't remember a whole family perishing in a fire in my lifetime," Roberts said. "It's just, 'Oh God.'"