The mother of a toddler found running along a highway in her pyjamas was later found "staggering" drunk by police.

The Masterton girl, aged 3, was found, distressed and wearing a wet nappy, by a passing motorist after midnight on July 21. The temperature was just 3 degrees Celsius.

The girl had pushed a chair up against a door so she could climb up to let herself out of the house, and was heading south in Opaki Rd, which doubles as State Highway 2.

Yesterday the woman, 27, whose name is suppressed, pleaded guilty at Masterton District Court to failing to provide supervision for someone under 14. She was sentenced to six months' supervision, and ordered to have alcohol counselling and go to a parenting course.

Earlier, the court was told she had put the girl to bed, with a DVD playing, about 7.20pm, before drinking with a friend at her house. The pair left at 10.30pm to visit a friend 1.6 kilometres away.

Police prosecutor Sergeant Gary Wilson said the mother was meant to be away for only 30 minutes, but was still out when her daughter awoke at 12.20am.

The girl went looking for her mother and was found wearing light pyjamas and socks by registered nurse Jenna Jeffcoat, who had been driving to Masterton after a shift at Palmerston North Hospital.

Ms Jeffcoat called police and wrapped the girl in a blanket in her car to keep her warm as they waited for police to arrive.

Mr Wilson said the girl was able to point out her house, with police later finding her mother "staggering up the road in an intoxicated state".

Outside court the mother said she was "embarrassed and angry" about her actions. She had drunk one bottle of wine before leaving the house.

The girl was now staying with grandparents, while her two other children had been temporarily removed from her care by Child, Youth and Family.

- © Fairfax NZ News