A woman has admitted killing her two babies who were found dead at the family's upmarket home.
Felicia Boots, 35, pleaded guilty to the manslaughter of 10-week-old Mason and his 14-month-old sister Lily on May 9.
Her plea on the grounds of diminished responsibility was accepted by the prosecution at the Old Bailey, and murder charges were dropped.
Mrs Boots, who trained as a hairdresser, was unable to appear at two previous hearings. She had been detained at a psychiatric unit and the prosecution's decision followed consideration of doctors' reports.
Mrs Boots and her investment banker husband Jeff had moved to the UK from Canada. He found the children dead when he arrived home to their house in an area of south London known as "nappy valley" because of the number of young families living there.
Boots appeared in the dock in a black suit and white blouse. She began crying as she was asked to stand to enter pleas on the two murder charges. Her voice shook as she replied in a Canadian accent: "Not guilty to murder, but guilty to manslaughter because of diminished responsibility."
Boots looked down and read from a piece of paper as she was asked to enter a plea to the second murder charge. Giving the same answer, she wiped away tears with a handkerchief and sat down.
Edward Brown QC, prosecuting, told the court: "This plainly is a tragic case." He said the Crown had closely examined the medical evidence and spoken to Boots' husband, who was in court.
He added: "The authors of the reports are clear and agreed in their conclusions as to Boots' condition as at May 9 and the reasons for her actions on that day. As a result the Crown has taken the firm view that it is not in the public interest to pursue the counts of murder but to accept the pleas as entered."
Boots, who was suffering from postnatal depression, was ordered to be detained at a psychiatric hospital.