Areica Hill says she awoke last Wednesday morning to the sound of a dog barking inside her house.
She knew it wasn't her dog, so she got up to see what was happening, and made an even more alarming discovery.
"The way my house is set up, I can look down the hall, and I see a white female lady bent over the tub with my two-year-old in the tub," Hill says.
Investigators say that woman was 22-year-old Elizabeth Hixon.
Hill and her boyfriend held Hixon down until the police arrived.
They say she told officers that she was there to provide care for the child, and Hixon's mother says the woman had "good intentions".
Prosecutors have not determined what charges are appropriate.