A woman drowned her four-year-old daughter in a bath before placing her on a coffee table in her back garden and setting fire to her body, a jury has been told.

Carly Ann Harris, 38, denies murdering her daughter, Amelia Brooke Harris, at her home in the village of Trealaw in south Wales.

At the start of the trial at Newport crown court, the judge, Mr Justice Picken, told the jury it was common ground between the prosecution and defence that Harris was suffering from a mental illness at the time of her daughter’s death.

Michael Jones QC, prosecuting, told the jury: “This case that you are about to hear concerns events that took place on 8 June this year at a house in Trealaw, Tonypandy.

“On that day, this defendant, Carly Ann Harris, killed her four-year-old daughter Amelia by placing her in a bath of water and deliberately drowning her.

“The defendant then took Amelia’s dead body out of the bath, covered her with a sheet, carried her downstairs and placed her body on a coffee table that was situated in the back garden, and then set fire to Amelia’s body.”

Jones told the jury: “You will be hearing evidence about Amelia’s injuries and her cause of death and the mental health issues that affect this defendant.

“The evidence you hear is not in dispute between the prosecution and defence. There is no dispute about what Miss Harris did that day or what took place before or after Amelia was killed by the defendant.

“You will be hearing psychiatric evidence from two experienced psychiatrists as to the issues that affected and continue to affect Miss Harris.”

On the day of the death, a neighbour, Megan Griffiths, said she heard a raised voice saying: “Mummy, Mummy, Mummy.” A short time later, Griffiths’ partner, Jake Barlow, heard screaming.

Griffiths saw Harris standing in the front garden and the defendant allegedly told her: “God will be with her. The angels have taken her.”

“She appeared, to Miss Griffiths, to be dazed,” Jones said. Griffiths dialled 999 and went into the back garden of Harris’s house and saw the remains of Amelia lying on the coffee table covered with a duvet.

When the police arrived at the scene, Harris told them: “The angels told me to do it. Just arrest me. It’s OK.”

The court heard that one of Harris’s two sons said his mother had not been well for about six weeks before the incident. Jones said the 17-year-old, who cannot be named, described how Harris had been suffering from anxiety and believed she and their family were being stalked.

The prosecutor said: “He described how she had suffered with anxiety and on occasions would come into his bedroom in the middle of the night and wake him up. He described how she would also stare out of the back window of their property and say people were stalking them.”

The son arrived home at about 10pm on 8 June to find his 11-year-old brother crying in the living room. Jones said: “The younger brother told him: ‘Don’t go out the back garden.’

“He asked why, and Harris entered the room and said: ‘Amelia has gone to heaven.’ She said: ‘Don’t go out the back, she’s gone to heaven and she’s coming back on Sunday.’ The son walked into the garden and once there saw the coffee table and after lifting the sheet up he saw his sister’s leg. He then ran into the house screaming.”

Jones said that earlier on the day of Amelia’s death, Harris’s friend Nicky Jones had taken her and Amelia shopping. She said Harris appeared to be the happiest she had been for some time.

Jones telephoned Harris at about 7.30pm to ask if Amelia wanted to go to a play centre the following day, to which Harris replied: “We can’t tomorrow because I haven’t got Amelia. She’s gone to heaven. She’s safe now.” Harris then told her friend: “I’m only messing.”

The prosecutor said Harris had been taking small amounts of amphetamines leading up to the incident but experts agreed she had not been suffering from drug-induced psychosis.

Dr Arden Tomison, a psychiatrist, diagnosed Harris with schizophrenia and said at the time she was suffering from “abnormality of mental function, which substantially impaired her ability to form a rational judgment”.

He said she appeared to have experienced paranoid and religious delusions and believed she had to kill Amelia to save the world, and was being tested by God, who would then return her daughter to her.

Jones said: “At the time of the act she was suffering such a disease of the mind that she knew the nature of what she was doing and intended to kill Amelia but she did not know what she was doing was wrong.”

Jones said Harris felt she was following God’s instructions. He said: “She told the doctor she was spiritually enlightened. She said as Amelia’s body burned, the clouds turned pink as her daughter went to heaven.”

The trial continues.