Holly Schnobrich, 24, was charged with two counts of felony neglect and public intoxication after he neighbors noticed her son trying to drive her around in their car, WRTV Indianapolis reported Thursday.
The boy and his 3-year-old brother were placed into the custody of the Department of Child Services, police said.
The Tippecanoe County, Ind., Sheriff's Department said authorities were called Sunday after neighbors told them they saw the boy behind the wheel.
"It was just bizarre," a police officer told WRTV. "I asked, 'Is this toddler driving your car?' She said, 'He's a good driver.'"
Schnobrich reportedly admitted taking prescription painkillers and sleeping pills before the incident, the television station report said.
The child reportedly also told police he was having trouble because he couldn't reach the pedals.