A MOTHER who sat and watched as her boyfriend murdered her child won an appeal yesterday against a historic conviction for culpable homicide.

The Court of Criminal Appeal ruled that the judge at Andrea Bone's trial had not spelled out clearly enough for the jury that it had to consider what she, as opposed to a parent generally, might have done to protect the infant.

Bone, 23, was eight and a half months pregnant at the time, and of extremely limited intellect.

Although the judgment means Bone's conviction for culpable homicide has been quashed, she remains guilty of cruelty towards 13-month-old Nicole. She had been jailed for three years for both offences, and the sentence will be re-assessed at a later hearing.

The grandfather of the dead girl condemned the appeal court's decision. Ian Berry told The Scotsman: "It's a disgraceful decision. She might have been freed by a judge, but she has not been freed by the public. She should have been locked up for life for what she did."

In 2002, Bone and her former boyfriend, Alexander McClure, 30, who was not the father, stood trial accused of murdering Nicole in a farm cottage where they had stayed at Forgue, near Huntly, Aberdeenshire.

The jury heard that as McClure assaulted the infant by banging her head against a concrete floor and swinging her, like a pendulum, into a wall, Bone sat on a sofa, sipping coffee and smoking roll-ups. McClure was convicted of murder and sentenced to life imprisonment, the judge Lord Abernethy ordering that he serve at least 13 years before he could apply for parole.

Bone was found guilty of the lesser offence of culpable homicide, by "witnessing and countenancing" the attack and wilfully failing to protect her child. It was the first conviction of its kind in living memory. She was also convicted of causing Nicole unnecessary suffering on earlier occasions when the child was ill-treated by McClure.

Bone served more than a year of her three-year sentence before she was freed pending the appeal.

Giving the appeal court's judgment Lord Macfadyen, sitting with Lord Cullen, the Lord Justice-General, and Lord Wheatley, said that "wilful failure" in the culpable homicide charge related to steps that could reasonably have been taken to protect the child.

Margaret Scott, QC, for Bone, argued that the test was not a wholly objective one, and the appeal judges agreed.

"In the question whether a parent witnessing an assault on a child could reasonably have acted to protect the child, it is not appropriate to test the matter by reference to a hypothetical reasonable parent; rather the test is whether the particular parent, with all her personal characteristics and in the situation in which she found herself, could reasonably have intervened to prevent the assault," said Lord Macfadyen.

The appeal judges held that Lord Abernethy had not given the jury sufficient guidance on that important issue. "In particular, it was important in this case that the jury should have had an explicit indication that it was relevant to the question of reasonableness to have regard to the physical and psychological condition of the appellant," added Lord Macfadyen.

Bone had been heavily pregnant, she was smaller and weaker than McClure, she suffered from personality disorders and her intellectual functioning was in the bottom 5 per cent of the adult population.

A psychologist had given evidence that her ability to stop McClure would have been significantly impaired.

Lord Macfadyen said the trial judge's failure to give sufficient directions to the jury amounted to a miscarriage of justice. "That is sufficient to result in the allowance of the appeal and the quashing of the conviction for culpable homicide."

Bone, now living in England, told the BBC: "I am relieved I can finally grieve for my daughter."