The 16-year-old, who cannot be named for legal reasons, attacked 51-year-old Valerie Danes in the Wilkinson store on Parliament Street in Nottingham on January 29.

The victim suffered a punctured lung and the girl pleaded guilty to wounding with intent.

But when she appeared for sentencing, Nottingham Crown Court heard that she had a long history of offending, including breaching Anti-Social Behaviour Orders (ASBOs).

She also has a record of self-harming and suicide attempts.

After reading a psychological report on the teenager, Judge Dudley Bennett decided to adjourn sentencing to next month to see if a hospital bed can be found for her.

He said: "Plainly, with someone with the kind of problems this girl has got, it is better for a suitable medical alternative to be found rather than simply throwing her into the system, probably indefinitely."

It has been reported the girl was 15 at the time of the attack and was living at the Radford Bridge Care Home in Nottingham.

She has a previous conviction for attacking another shop worker with a screwdriver.

She started offending at the age of nine when her father died and was given her first of two ASBOs at the age of 12 after she started hanging around police stations and danced on cars to grab the attention of cops.

Two periods of juvenile detention have done little to stop her offending and she once tried to kill herself in a police station.

Claims have been made by the girl's 57-year-old grandmother that the attack on the Wilkinson worker could have been avoided had her granddaughter received proper support from social services.

The woman says that the 16-year-old shouldn't have been at Radford Bridge as she was classed as high risk. But there were no places available in a secure unit. The grandma claims that far from being supervised, the girl was allowed out of Radford Bridge and even given a bus pass.

A spokesman for Nottingham City Council confirmed that the case is being investigated by the Safeguarding Children's Board.