Watson told the court she had left the boy with his brother
A four-year-old boy walked half a mile from his Edinburgh home and crossed a busy road while the woman looking after him went shopping, a court has heard.
The child was spotted by a driver, who saw the boy alone at the side of the 30mph dual carriageway in Edinburgh.
At Edinburgh Sheriff Court, Marie Watson, 33, admitted neglecting the boy by leaving him on 4 July without adult supervision.
Sheriff Kenneth Maciver called for background reports before sentencing.
He said would also decide later whether to refer the case to a childrens' hearing.
Watson, who was responsible for the boy at the time, was arrested after reaching home 90 minutes after the boy was discovered.
Fiscal depute Kate Mulligan, prosecuting, said the child was spotted by a couple driving in Silverknowes Road in the city about 1430 BST on 4 July.
"They became concerned when they saw the child walking alone on the side of the road," the prosecutor said.
"They stopped the vehicle and alerted another driver then attempted to speak to the boy and ask if he was lost.
"He continued walking."
Ms Mulligan said the driver's wife had got out of the car and walked behind the child while they waited for police to arrive.
"She managed to stop and calm the child down as he had become slightly agitated by people asking questions of him."
When police arrived, the boy told them he had come from the Muirhouse Park area.
"He was able to take officers back to his home address," Ms Mulligan said.
"In order to get to where he was found, he would have had to cross Muirhouse Parkway.
"There were a number of vehicles on the parkway at that time," she added.
Watson told police she had left the boy in the care of his eight-year-old brother while she went to the shops.
She said the brothers had been out playing with friends but had become separated and the younger child wandered off.
Watson is expected to be sentenced next month.