Stoni Blair and Stephen Berry- ages 13 and 9 at the time of their deaths, have not thawed out for medical examiners to determine their cause of death. The mother, 35-year-old Michelle Blair, has been charged with five felonies and has admitted to killing them.
The children's great aunt, who is a retired Detroit police child abuse investigator, is caring for the surviving siblings.
Angela Gordon caring for the surviving siblings said Michelle had shunned the family.
"She estranged herself from the family," Gordon said. "I had not seen her for two years and not spoken to her in about a year and a half."
For 26 years Angela Gordon was a successful child abuse investigator and an expert in detecting some of Detroit's worst cases of child abuse.
Were there any clues any signs she should have picked up on?
"Well, that's impossible when somebody estranges themselves from you," Gordon said. "I would go to the home, I would knock on the door. I would bang on the door and got no response.
"I knew they were in there. She had those children to the point where they wouldn't open the door."
Gordon said that at the time, it was not a troubling sign.
"No because I talked to neighbors and I said 'Have you seen her lately, have you seen the kids,'" Gordon said. "(They said) 'Oh yeah, we've seen them, we've seen the kids.' And maybe I didn't specify all four - but the neighbors did say that they had seen them."
Gordon recalls all four children as fun loving, adding that she helped the children and their mother until the relationship broke down.
"I had helped her so much throughout her life," Gordon said. "Either paying gas bills, bringing food, bringing clothes. And at some point, I said, 'I have to stop, I can't keep doing this, I'm retiring and I cannot keep supporting you like this.'
"Then she stopped contacting me. And the last time she contacted me was a year and a half ago for a $900 gas bill. I paid it and never heard anything else from her."
Gordon says she now knows the surviving siblings were well aware of the deaths and then concealment of their beloved brother and sister.
"I don't want to get into what they know," she said. "But they both know the children are gone. They both know the children are dead."
FOX 2: "Do you think they were living in the house with that knowledge?"
"Sure," Gordon said.
A couple years ago Blair pulled the children out of school to home-school them.
But according to the state of Michigan's home schooling standards, there is no requirement for reporting to the state, unless the child has special needs.
Home school reporting to the state is voluntary on parents' part.
Gordon said that right now the family needs prayers for the deceased children, and those still alive.