A mother has admitted killing her three disabled children, but denies murder.
Tania Clarence, 42, sobbed as she appeared at the Old Bailey to plead guilty to the manslaughter of four-year-old Olivia and three-year-old twins Ben and Max on the grounds of diminished responsibility.
She is said to have smothered the children at their home in New Malden, in April.
The children, who all suffered spinal muscular atrophy (SMA) and faced a shortened life expectancy, were found dead by the family's devoted nanny and a neighbour.
Mrs Clarence's husband Gary, a 43 year-old director at the City investment bank Investec, had been in their native South Africa with the couple's eldest child at the time.
Police were called to the family's five-bedroom home April 22 where they discovered the children, who were pronounced dead at the scene.
Mrs Clarence was treated for cuts at St George's Hospital in Tooting, south London, and charged on April 24.
Appearing at the OId Bailey, she denied three charges of murder, but pleaded guilty to the lesser charge of manslaughter on the grounds of diminished responsibility.
Asked how she pleaded to each count she sobbed as she replied: "Not guilty to murder but guilty to manslaughter."
Her husband sat in the well of the court as she entered the pleas.
The prosecution asked for more time for their psychiatrist to consider the case and the judge, Mr Justice Nicol, adjourned the case until October 3.
A provisional trial date was set for 23 February 2015 and the court was told the case is expected to last up to four weeks.
Mrs Clarence was remanded to a secure hospital under the Mental Health Act for assessment by psychiatrists.
Defence barrister Jim Sturman QC confirmed the basis of the pleas to manslaughter was diminished responsibility.
The prosecution are expected to indicate at the next hearing if they will accept the plea of manslaughter on the grounds of diminished responsibility. Mrs Clarence waved to the public gallery and wept as she was taken from the dock.