Virginia Castille says she saw a TV news report about the four-year-old boy and knew it was her grandson, Sir Kenneth Davis. Castille says the boy's mother, who is her daughter, died of cancer a few years ago.
Officials have taken custody of the boy. Castille says she wants to take care of her grandchild.
"I just started weeping and crying. I said, 'That's my baby.' I say, 'I know him, that's my baby,'" said Castille.
Children's Protective Services won't confirm Castille's claim, but the agency is encouraging any family to contact them.
CPS spokesperson Estella Olguin says the boy appears healthy and is talkative. There's no word if the boy has any siblings.