Constance Marten has tearfully given her account of how her daughter Victoria died, and how she kept the body in a Lidl bag, during her retrial at the Old Bailey.
She said that she was worried that people would think she was an "evil mother" or a "murderess."
She said she had just fed the newborn baby while staying in a tent on the South Downs near Newhaven in January 2023. She said she and Mark Gordon were trying to hide her baby from the authorities who had removed her previous four children.
Marten, 37, and Gordon, 50, deny charges of manslaughter by gross negligence and causing or allowing the death of a child.
At a first trial last year they were found guilty of concealing the birth of a child and perverting the course of justice by not reporting the baby's death.
The couple's baby girl was found dead in a shopping bag covered in rubbish, in a shed on a Brighton allotment in 2023.
Marten told the court on Friday that while staying in the tent, she had fallen asleep and flopped forward. When she awoke, her forehead was on the ground.
"I just woke up and I felt something was wrong," she said. "I think Mark woke up at the same time."
"I just took her out of my jacket and she was just completely limp. She was pale and her lips were a kind of purply colour."
Marten described realising that Victoria had died.
"I just knew she wasn't alive and I felt very responsible," she said, adding: "My assumption was that I had fallen asleep on her."
"It was at first disbelief. Not wanting to think that she wasn't alive," Marten said.
"I just knew she wasn't alive, but Mark wouldn't believe it and he tried to do CPR on her."
"There was a bubbly gurgling sound from Victoria," she told the court.
She wept as she described how the CPR did not work.
"There was no heartbeat. There was no breath. She was completely limp," she said.
"I held onto her for about a couple of hours on my chest."
"I wrapped her up in a headscarf and said some words over her and then put her in the Lidl bag," she told the jury.
Marten said that a few days later she went to a Texaco petrol station in Newhaven and filled a glass bottle with some petrol.
"I was toying with the idea of cremating her body so the authorities wouldn't find her," she said. Marten said she was worried people would think she was "some evil mother" or a "murderess."
She said that from the petrol station, she and Gordon walked to the train station in Newhaven and then got a bus to Brighton beach where they ate some food, putting the packaging on top of Victoria's body in the Lidl bag.
Marten said that Gordon usually carried the bag with Victoria's body in it.
"I couldn't bear to," she said.
The retrial continues.