A toddler was found wandering a Dallas parking lot last week after his grandmother lost track of him during a shopping trip, thinking he was "knocked out" on medicine in the car.

Cynthia Williams, 57, and the child's cousin Tracy Whetstone, 38, were arrested Tuesday on child abandonment charges, court records show.

Both remain in the Dallas County Jail with bail set at $25,000.

Cynthia Williams and Tracy Whetstone, the boy's cousin, were being held in the Dallas County Jail.

Police were called shortly before 7 p.m. Tuesday to the T.J. Maxx on Preston Road after an employee there found the 3-year-old wandering the busy parking lot outside.

After looking around for the boy's family, the employee called 911 to report an abandoned child.

Williams showed up a half hour later and told police she'd gone into the T.J. Maxx to make a return, while Whetstone went to the nearby McDonald's for a bit to eat, leaving the child alone in the back seat.

"He was asleep in the car," Williams said, noting that she'd given him medicine for his congestion. "He's usually knocked out.

But police said the pair didn't realize their mistake until they were a dozen miles away at their next shopping stop in Plano. Failing to notice that the boy had gotten out, they drove to a Ross store in Plano.

That's when they realized the toddler was gone and drove back to the T.J. Maxx.

The child was handed over to his mother at the store, police said.