Hospital bosses used killer nurse Lucy Letby as a poster girl to celebrate raising money for a new neonatal unit hours after she murdered a baby boy and tried to kill his twin brother, MailOnline can reveal.

Letby, who is Britain's most prolific child killer, was today sentenced to a whole life order for murdering seven babies and trying to kill six more. In a final insult to her victims' families, she refused to appear in court to hear how she ruined their lives.

Now, a chilling image has been uncovered of Letby celebrating with four colleagues on August 6, 2015, after a fundraising campaign for a new baby unit at the Countess of Chester Hospital - where she committed her heinous crimes - passed the £1.5million mark.

Letby is seen flashing a huge grin for the cameras knowing she had just murdered a baby and attempted to kill his twin.

Just two days earlier, a mother had walked in on the evil killer trying to murder her son, known as Baby E, after arriving on the unit with milk. She found him with 'blood around his mouth' before he died from a fatal bleed which is thought to be caused by Letby interfering with his nasogastric tube.

Then on August 5, a day before the photo of Letby was published in a local newspaper, she attempted to kill Baby E's twin, Baby F, by spiking the child's feeding bag with insulin.

In a newspaper article killer nurse Lucy Letby (left) celebrates raising money for a new neonatal unit - the day after trying to kill a baby - and two days after she murdered his twin brother

Lucy Letby, who is Britain's most prolific child killer, was today sentenced to a whole life order for murdering seven babies and trying to kill six more

Letby was one of the faces of the 'Babygrow Appeal' to raise money for a new neonatal unit at the Countess of Chester Hospital - which is where this photo from 2013 was taken

Blood samples later showed 'extremely high' insulin levels and very low blood glucose levels - proving he had been injected. The blood glucose level was so low that, if left untreated, it might have caused Baby F convulsions, coma, apnoea, irreversible brain damage and death.

Disturbing text messages also revealed the lies Letby was feeding her colleagues at the time. After Baby E's death, a colleague texted the killer and asked if she had been caring for the twins.

Letby said: 'News travels fast. Who told you? Yeah I had them both. Was horrible.'

The nurse later replied: 'I just really feel for his parents but for you too. You've had some really tough times recently.'

Before Letby returned to work she texted a second colleague, who told the killer she has had some 'very bad luck'.

Letby replied: 'Not a lot I can do really. He had massive haemorrhage could have happened to any baby x.'

On August 9, 2015, days after trying to kill Baby F, Letby texted: 'I said goodbye to Baby F's parents as Baby F might go tomorrow. They both cried and hugged me saying they will never be able to thank me for the love and care I gave to Baby F and for the precious memories I've given them. It's heartbreaking.'

The colleague said: 'It is heartbreaking but you've done your job to the highest standard with compassion and professionalism.[...]'

Letby then replied: 'I just feel sad that they are thanking me when they have lost him and for something that any of us would have done. But it's really nice to know that I got it right for them. That's all I want.'

Letby targeted innocent babies while working on the neonatal unit at the Countess of Chester Hospital between June 2015 and June 2016.

She was convicted of murdering five baby boys and two baby girls at the Countess of Chester hospital and attacking other newborns in a year-long killing spree.

Letby sent disturbing text messages after killing Baby E and then trying to kill Baby F hours later

Letby was one of the faces of the Chester Standard's partnership with the Countess of Chester Hospital to raise money for the new neonatal unit.

By 2017, the Babygrow Appeal - which is where the picture of Letby holding a babygrow comes from - raised more than £2.4million ahead of a formal planning application, which was granted in 2018.

In 2013, Letby featured in the early stages of the campaign where she told readers she had qualified as a children's nurse from the University of Chester in 2011 and had been working on the neonatal unit since graduating.

When asked what her role as a neonatal nurse included, she disturbingly said: ''My role involves caring for a wide range of babies requiring various levels of support.

'Some are here for a few days, others for many months and I enjoy seeing them progress and supporting their families.

Letby worked on the neonatal unit at the Countess of Chester Hospital between June 2015 and June 2016

'I am currently undergoing extra training in order to develop and enhance my knowledge and skills within the Intensive Care area and have recently completed a placement at Liverpool Women's Hospital.'

She said that she hoped a bigger neonatal unit would 'provide a greater degree of privacy and space for parents and siblings'.

Two years later, Letby then featured in the celebratory photo after the fundraising for a new baby unit passed the halfway mark.

At the time, the article said that the neonatal unit was caring for around 450 babies a year. The improved unit eventually opened during the pandemic in 2021.

At Letby's sentencing today, the heartbroken mother of the twins said she cried 'not again' when her second son became unwell. The babies were a result of several rounds of IVF - and the family had accepted they may never have children.

When she found out Letby was a murderer, she said: 'We felt cheated, deceived and utterly heartbroken once more.'

Harrowingly, she described how she had to grieve in front of Letby who bathed her son for the final time and dressed him in a woollen gown.

'He was buried in that gown, a gift from the unit chosen by Lucy,' she added.

The mother continued: 'Lucy was aware of our journey and deliberately caused significant harm and cruelty to our boys,' she says.

As Letby was sentenced today, new photos have emerged of her on a hen do with a large group of friends

Letby is seen smiling as she poses with her friends. She has now been confirmed as Britain's worst ever child killer

'No children in the world were more wanted than them.'

Baby F, now eight, is living with complex learning difficulties - something his parents believe is a result of him being poisoned with insulin.

The mother said: 'Nothing can change what has happened to us, we are living with a life sentence because of Lucy's crimes.'

She continued: 'We have been living a nightmare but, for me, it ends today. I refuse to wake up with my first thought be about my boys being harmed. Lucy no longer has control over our lives. She holds no power or relevance in anybody's life. She is nothing.'