She told Dr Phil: "I'm not making excuses for her. I want to find out what's wrong with Casey. I know that there's something wrong."
She speculated that Casey may have suffered from a seizure on the day Caylee died, adding that in November 2007, she'd had one so severe that her fiance Jesse Grund had called 911.
But then she was forced to admit: "I don't know if she had a seizure that day and blacked out.
"I don't know why she's having a seizure. Does she have a brain tumor, were the seizures caused by stress?"She could also offer little or no reason for her daughter's bizarre behavior during the time that Caylee was missing.
During that time the young mom partied at clubs, got a tattoo that read "Bella Vita" and spun a web of lies about Caylee's whereabouts.
Cindy claimed that it might be the result of gran mal seizures, but ultimately she was only left with questions about her child.
She wondered how: "this caring young person who cared about everybody, loved kids and then all of a sudden something tragically happens to Caylee and Casey completely goes off the deep end?"
Cindy Anthony admitted to McGraw that she has a history of making excuses for her 25-year-old daughter, but she did admit that they noticed a change in her daughter after Caylee was born.
She recalled: "Looking back now, I'm almost wondering if she didn't develop post partum schizophrenia or some issue after her pregnancy, a hormonal type of illness."
George Anthony, who Casey's lawyer's claimed had abused his daughter when she was younger, took a harsher stance.
He said: "To me, in my mind, one and one adds up to two. She's responsible for Caylee. She's her daughter and Casey is responsible for Caylee no matter where she was at or what happened."
George Anthony admitted that he can't rule out that his daughter might have driven around with a dead Caylee in her trunk.
"Some parts of me do believe that she was possibly back there," he told Dr Phil.
The second part of Cindy and George Anthony's interview with McGraw airs Wednesday.