Ms Marten and Mark Gordon are on trial accused of the manslaughter of their newborn daughter.
Image source, GMPConstance Marten has denied harming her newborn baby girl and told a jury she “did nothing but show her love”.
Giving evidence in court, Ms Marten said she believed her baby died on 9 January last year and that she wondered if it was something she “will ever move on from”.
Ms Marten, 36, and partner Mark Gordon, 49, both deny the manslaughter by gross negligence of their daughter Victoria.
Her body was found in a Lidl bag in a shed in Brighton on 1 March.
Ms Marten and Mr Gorgon had allegedly been living in a tent in wintry conditions on the South Downs.
On Thursday, Ms Marten went into the witness box to give evidence in her defence after Gordon declined the opportunity earlier in the week.
Defence barrister Francis FitzGibbon KC asked her: “Did you do anything to harm baby Victoria?”
Ms Marten replied: “Absolutely not.”
Mr FitzGibbon said: “Did you do anything cruel to baby Victoria?”
Ms Marten said: “No. I did nothing but show her love.”
She told jurors she did not expose her baby to cold or allow her to get too hot so far as she was aware.
Mr FitzGibbon said: “So far as you are concerned, did you give her anything less than the proper care you thought she deserved?”
Ms Marten replied: “I gave her the best that any mother would, yeah.”
Referring to her daughter’s death, she said: “I do not think it is anything I will ever move on from.”
She said she felt “guilty”, adding: “I think initially it was disbelief, shock, intense grief.”
Greater Manchester Police had launched a nationwide search after a placenta was found in the couple’s burnt-out car by the motorway near Bolton, Greater Manchester, on 5 January 2023.
It is alleged the defendants went on the run because they wanted to keep their daughter, after four other children were taken into care.
Days after the pair were arrested on 27 February, Victoria’s badly decomposed body was found in a Lidl bag inside an allotment shed in Brighton, East Sussex.
While the cause of her death is “unascertained”, jurors have heard she could have died from the cold or co-sleeping.
Ms Marten told police Victoria died when she fell asleep in the tent while holding her under her jacket.
The court has heard Ms Marten had previously been warned by social workers of the risks of falling asleep with the baby on her and that a tent would be “wholly inappropriate for a baby to live in”.
The defendants, of no fixed address, deny manslaughter by gross negligence, perverting the course of justice, concealing the birth of a child, child cruelty and causing or allowing the death of a child.
The trial continues.