Workers at a Fort Mill bar called police after witnessing Gretchen Kinnear give her son shots of beer.
The police report says the four-year-old boy told investigators his mom gave him a drink that tasted funny, made him laugh, and made him dizzy, and that his mother also gave him the same drink at home.
It also says the mother admitted giving the child wine once or twice a week, but said it was not to get him drunk or keep him quiet.
The suspect's brother says he is shocked about the allegations, and that his sister is a good mother who loves her son.
"She's a single mom, and she loves him to death, and it's just very surprising," Doug Kinnear said. "I think she probably let him have a sip of beer, but not ever to get him drunk or anything."
Kinnear is facing charges of contributing to the delinquency of a minor.