The Crown Prosecution Service (CPS) has accepted Tania Clarence’s guilty plea to manslaughter on the grounds of diminished responsibility, the Old Bailey has heard.
The 42-year-old mother from New Malden, south-west London, has denied murder.
The children, who all had type 2 spinal muscular atrophy, were found at their home on 22 April.
‘Exhausting, distressing, debilitating’
The prosecution said Mrs Clarence killed her three-year-old twin sons Ben and Max and daughter Olivia, aged four, because she was depressed and wanted to end their suffering.
Mrs Clarence, who was not in court, will be sentenced on 14 November when she is likely to face a hospital order.
Jim Sturman QC, defending, told the court: “This offending did occur whilst Mrs Clarence was suffering from an abnormality of the mind.
“She was manifesting stress throughout the life of the children by their suffering and caring for three children with this condition was exhausting, distressing, debilitating and turned out to be overwhelming.”
Prosecutor Zoe Johnson QC said Mrs Clarence had previously believed that the quality of her children’s lives was more important than their longevity, which was “entirely understandable”, she said.
BBC correspondent Matt Prodger, who was in court, said Mrs Clarence could “see no hope for the future” and could no longer cope with caring for her children.
The defence asked that she should serve any sentence in hospital, he reported.
At a previous hearing, the court heard that Mrs Clarence confessed to killing three of her children at her home.
Mrs Clarence left three notes before allegedly smothering the children.
She then tried to kill herself.
The mother-of-four was discovered bleeding and crying by her distraught nanny and a neighbour, who had gone to the home after becoming concerned for her safety.
Spinal Muscular Atrophy (SMA)
- A genetic disorder that affects nerves responsible for muscle function
- It causes the muscles to waste away over time, which can lead to skeletal deformities, such as abnormal curvature of the spine, and problems walking, eating, drinking and breathing
- It is rare, affecting one in every 6,000 babies born in the UK
- However, the most common of the three forms of SMA is the most severe, and usually proves fatal in a child’s first year
- Children with a milder form of the disorder can live to adulthood
- The mildest form of SMA does not usually affect life expectancy