A NANNY was warned last night that she faced a prison sentence after she admitted shaking to death a six-month-old girl in her care.

Caroline Jongen died as a result of brain damage after Australian-born Louise Sullivan shook her violently for up to 10 seconds in a panic. Sullivan was trying to revive Caroline after fearing she had had a fit while feeding. She later described Caroline as the "sweetest little girl I have ever seen".

Sullivan, 27, was found to have an IQ of just 81. She suffered from thyroid deficiency and had to take medication.

Her trial for murder, expected to last five weeks and with inevitable echoes of the Louise Woodward case, was due to start yesterday. But at the last moment she pleaded guilty to involuntary manslaughter, which was accepted by the prosecution.

The judge, Mr Justice Mitchell, warned her she may face a jail sentence when the hearing resumes in two weeks' time after social services and medical reports have been prepared. He said: "I am sure you realise that the fact I am giving you bail does not close any of the options open to me. Do not mislead yourself about that."

Sullivan, looking pale and nervous and wearing a black suit with her blond hair tied back with a red ribbon, spoke just once during the hearing to say: "Guilty of manslaughter on the basis of involuntary manslaughter". Mothers tell why they sacked nanny

Caroline's parents, Dutch-born investment director Marcel Jongen, 42, and his French-born wife, Muriel, a financial analyst, sat just six feet away from her.

Sullivan had arrived from Australia with childcare qualifications, first aid certificates and glowing references in April 1997. The court was told that one of the techniques she had been taught at college was called "shake and shout". However, the Crown stressed that would not have been an appropriate treatment for a young baby, such as Caroline, suffering a fit.

Sullivan got her job at the Jongens' home in Cricklewood, north London, through the London-based Kidz Unlimited agency.

Sullivan claimed that Caroline had hit her head on a bath rail but she had not mentioned this to the family. Sullivan said "that the baby went into something like a fit". She panicked and told police she "may have shaken her a little bit". The baby died in Great Ormond Street Hospital on 21 April last year after a ventilator maintaining her breathing was switched off after four days.

But within 24 hours, she had been charged with causing grievous bodily harm, as Caroline's medical team became increasingly convinced that her critical injuries were the result of shaken baby syndrome.

In September, Sullivan was charged with murder following an intensive investigation by London police, which included sending a team of detectives to Australia to gather evidence about Sullivan's employment history.

The police have since revealed that, while Sullivan claimed spotless credentials, she had been dismissed from four jobs, twice for inappropriately shaking a baby.

The investigators were particularly careful and thorough in the conduct of their inquiries because of the chilling similarity to the case of the British nanny Louise Woodward, who was found guilty in the US of manslaughter after the death of baby Matthew Eappen, who was in her care. Woodward's jury conviction was later overturned by a judge and she is now studying law in Britain.

Detectives were sent to the US to liaise with members of the team that prosecuted Woodward and to hold meetings with the judge who rejected the jury's decision.

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