Jessica Whelan, the four-year-old girl with neuroblastoma whose heartbreaking photo touched thousands around the world, has died after a 13-month battle with the illness.
In a post to their Facebook page, Jessica's father, Andy Whelan, of Oswaldtwistle, Lancashire, shared the news that his little girl had "finally found peace" on Sunday morning.
"No longer does she suffer, no longer does she feel the pain of the physical constraints of her body," he wrote.
Mr Whelan expressed that he felt both sadness and relief at her passing. "Now my princess has grown her angel wings and has gone up to play with her friends and loved ones. She will now watch down over her little brother and ourselves until one day we are reunited again."
The grief-stricken father also wrote of his daughter's last moments, describing that his little girl finally allowed him to hold her in his arms. "I told her again that it was okay for her to close her eyes and go to sleep and I kissed her forehead and her lips numerous times," he said.
Within eight hours of their cuddle, Jessica took her last breath. "It seems like this is what she needed to finally allow her to find comfort in her passing," Mr Whelan wrote.
"I am so glad that I could give her that comfort in her final hours," he said. "She passed peacefully and calmly with not even a murmur."
Writing that she was a "daddy's girl", from the beginning right through to the end of her life, Mr Whelan described that he feels as though a part of himself has been torn away.
The heartbroken father thanked those who had shared and supported the family on their journey - and asked for privacy as they mourn their "beautiful princess".
"Fly high my beautiful princess, watch over me, mummy and James," Mr Whelan wrote, alongside a picture of his little girl. "Ride free on horses in heaven and enjoy being with loved ones and free from your pain."
The grieving father added that he would never forget Jessica – and is honoured to call her his daughter.
"I love you more than words can convey, much more than you will ever know. Goodnight Jessica Mae, sweet dreams, rest in peace."
Jessica was diagnosed with stage 4 Neuroblastoma in September 2015. In October this year, the little girl's oncologist told her heartbroken family that she had only months to live.
Shortly afterwards, Mr Whelan shared a photo of his little one to Facebook, describing it as the "hardest photograph I have ever made."
"This was taken at a moment where we as parents could offer no comfort - Jessica pushing us away as she rode out her searing pain in solitude", he wrote.
"This is the true face of cancer, my baby girl's blood vessels protruding from beneath her skin, a solitary tear running down her cheek, her body stiffened and her face contorted in pain."
At the time Mr Whelan explained that by sharing the photo of his daughter's suffering, he wanted to educate and shock "those that see it in its context".
"Perhaps by seeing this photo," he wrote, "people not in our position will be made aware of the darkness that is childhood cancer, perhaps these same people may be able to do something about it so that in the future no child has to suffer this pain, so that no parent has to bear witness to their own flesh and blood deteriorating daily."
Mr Whelan added that research needs to be done – and that cures urgently need to be found.
"Please I beg of you, as a heartbroken father," he wrote, "it is too late for my daughter, but childhood cancer needs to be cured. No family should have to go through this hell."
Rest in peace, Jessica.
Read Mr Whelan's post in full, below: