The mother of the third baby to have been murdered by Lucy Letby in June 2015 has told an inquiry she kept pushing for the truth even when people thought she was "bonkers".

The Thirlwall Inquiry is investigating how Letby, 34, was able to murder seven babies and attempt to murder seven more at the Countess of Chester Hospital between June 2015 and June 2016.

Over two weeks, parents of babies involved in Letby's criminal trials are giving evidence at Liverpool Town Hall on how they were treated by the hospital and what they feel should be done in future to prevent such cases again.

A court order prohibits reporting of the identities of the surviving and dead children involved in the case, and the hearings over the next fortnight are being privately held, with media able to follow some sessions through an audio link.

Letby was found guilty of murdering Child D, who had died in June 2015, by injecting air into the baby's bloodstream. Child D's mother says the neonatal unit nurse attacked her baby girl three times, and said the revelation Letby had later looked her up on Facebook was "hard to digest" as they had barely spoken to each other.

Giving evidence to the inquiry on Tuesday, September 17, the mother said she kept "pushing" for "the truth" and a full inquest for Child D, as the reports she received from the hospital "did not add up".

A post-mortem examination for Child D recorded the death as pneumonia and acute lung injury, while a report of the Child Death Review Panel at the hospital listed the cause of death as "complications of delivery". The inquiry has heard neither conclusion explained Child D's sudden and unexpected collapses and death.

She said she could not leave the death "unexplained" and pushed several times for a full inquest, and instructed solicitors in September 2015. Having obtained medical records for Child D, she also pointed out to the hospital where it had not followed relevant NICE guidelines and protocol for events around Child D's birth.

Answering questions put forward by Rachel Langdale KC, counsel to the inquiry, the mother said her investigations and Letby's criminal trial took their toll on her, saying she was "no longer a friend, or a daughter, or a wife" to those who knew her, and thought she was 'losing her mind' as she talked about taking her investigation to the police.

"It was hard to keep sane as I didn't know if I was doing right. This was my daughter's voice – I couldn't give up," she said, adding that people thought she was "bonkers" when she talked about taking the case to the police.

She said a version of the RCPCH report she received in April 2017 did not address her concerns and was "just rubbish".

The parents also insisted on meeting former medical director Ian Harvey at the hospital in May 16, 2017. They had been due to hold a meeting that day, and had received a call from Cheshire Police that morning that there was a police investigation. When they arrived at the hospital, they were told the meeting had been cancelled.

The mother told the inquiry: "I said I don't care – I was there, he was there, I was not going away until I had seen him."

A short meeting followed in which the mother recalled: "He didn't want to speak – he said it was not up to him to speak any more," something which she found "upsetting".

The mother said at that point, they were "very close to getting answers", but the launch of the police investigation left her and her husband in "limbo" until the trial took place.

With the mother being called as a witness in the Letby trial, she said she had to be in a "bubble" until being called, and her husband – who attended each day – was not able to say what had happened, but would "sometimes come home upset".

Asked for her views on Letby, the mother said with the benefit of hindsight, her "instinct" was she felt "uneasy" in her presence.

"When I went to visit my daughter, she was just there in the room. She had no reason to be in the room. She was just around doing nothing." The mother said she asked her husband if Letby could leave.

Asked for suggestions on what could help prevent such incidents in future, the mother suggested a camera for an incubator, and highlighted that when she was taken to the hospital's Lavender Suite after Child D's passing, she had had to go through the maternity unit, where mothers were ready to give birth.

She said that was "a shocking way of dealing with grieving parents", as she walked by beds with expectant mums with balloons, smiling, and she felt sorry for those parents who may have been "distressed" seeing her.

The mother added she felt even more heartbroken when, in the aftermath of Child D's death, she was asked if the baby girl could be an organ donor, but minutes after agreeing – having been informed there was a child who needed a new heart – hospital staff told her that was no longer possible as there would need to be a post-mortem examination for Child D.

At the end of her evidence, Richard Baker KC - representing several of the families in the inquiry - re-read Child D's mother's victim impact statement which was first heard at Letby's August 2023 sentencing.

Lady Thirwall, chair of the inquiry, praised the mother for pursuing answers "at great personal cost", which will benefit the inquiry.

"You have never given up," Lady Thirlwall told the mother.

Letby, from Hereford, is serving 15 whole-life orders after she was convicted at Manchester Crown Court of murdering seven infants and attempting to murder seven others, with two attempts on one of her victims.

The inquiry is expected to sit until early 2025, with findings published by late autumn of that year.