A seven-year-old girl wrote a "thank you letter" to a judge who jailed her father for killing her mother, the High Court has heard.
The youngster had been present when her father stabbed her mother to death, a hearing in London was told.
She had tried to help and was found covered in blood near her mother's body.
Her father had admitted manslaughter on the grounds of diminished responsibility and been jailed for a minimum of more than 10 years.
Detail has emerged in a written analysis of the case by a judge who sits in the Family Division of the High Court.
Social workers had asked Mr Justice Keehan to make decisions about the little girl's future.
Mr Justice Keehan said he had given his approval to the youngster being placed in long-term foster care.
He said nothing could be published which might identify the little girl.
"(The little girl) was not only present when her mother was killed, but she suffered injuries inflicted by her father as she bravely sought to protect her mother," said Mr Justice Keehan.
"She was found by the emergency services in the same room as her mother's dead body. (She) was covered in blood."
He added: "On hearing of her father's conviction and sentence of imprisonment she wrote a 'thank you letter' to the judge who presided over the criminal proceedings."
Mr Justice Keehan said the youngster had "suffered a horrendous trauma" and the "severe loss of her beloved mother".