NSW mum jailed over daughter's death

A woman who failed to prevent her abusive partner beating her 12-year-old daughter to death has been sentenced to at least 18 months jail.

Supreme Court Justice Peter Hamill in Newcastle said on Friday the mother had failed in her duty of care to protect her daughter in a case he described as one of gross criminal negligence.

The child's stepfather had left their NSW Hunter region home after the beating to drive to the local bottle shop three kilometres away, giving the woman a chance to either call an ambulance or take her seriously injured daughter to hospital.

She did nothing and the girl was found dead in her bed next morning, her body giving up after years of abuse, the judge said.