Family and friends have paid tribute to a "thoughtful and sassy" five-year-old girl who "made everyone smile".
More than £6,000 has been raised in the last week for little Luna Ivy Webster, from Medway, who suddenly died last Saturday (October 4).
Luna's mum, Jess Gardner, is being supported by her friend Aimee Riddell, who is helping fundraise to ease the family's financial stresses during this time.
Speaking on behalf of Jess, who is currently pregnant with her second child, Aimee told KentOnline: "Luna was a bright, thoughtful and sassy girl who made everyone smile.
"She was a showstopper - born to be on stage with the many songs she liked to make up.
"Her favourite things were the character Stitch from Lilo and Stitch, and KPop Demon Hunters, which came out recently.
"Luna had a huge mothering instinct, with a ton of baby dolls and was constantly telling people about her baby brother, who is due at the end of November.
"Jess raised her with such respect and understanding - she has always been the mother I aspire to be."
Luna was born with a condition known as Hypoplastic Left Heart Syndrome (HLHS).
Alarm bells were first raised by doctors when Jess had her 20-week scan.
HLHS is a rare condition that is caused by an abnormal development before birth and affects 1 in 5,000 babies, with around 200 new diagnoses annually across the UK and Ireland.
The left side of the heart - including the ventricle and aorta - is underdeveloped, which makes it unable to pump blood around the body effectively.
At around 35 weeks (eight months) into her pregnancy, Jess had an emergency C-section.
Luna required several emergency procedures and suffered from cardiac arrest when she was just over a month old.
Overseen by specialists at the Evelina London Children's Hospital, there were three major operations the youngster needed to reconfigure her heart and improve blood circulation.
Two took place within her first year. These included the Norwood procedure in February 2020 and the Glenn procedure, which happened three months later.
"Jess's whole life was about Luna," Aimee added. "Due to Luna's condition, Jess had to be her full-time carer.
Luna was loved by so many, but no one more than her devoted, strong mummy Jess.
"She couldn't go near anyone who had a cold. For Luna, a common cold would mean extra strain on her heart and would land her in hospital.
"As she got older, she got tired quicker and had to take rests. She relied on a wheelchair to avoid overexerting herself.
"She also had a permanent blue tint to her nails and lips due to the lack of oxygen."
On Tuesday, September 23, Luna went in for her third and final operation.
Doctors carried out the Fontan procedure, a form of open-heart surgery specifically for children, which would have improved her life expectancy.
However, on Saturday (October 4), Luna passed away. She was just five years old and would have celebrated her sixth birthday on November 5.
A GoFundMe page has since been launched, and at the time of writing, around £6,500 has been raised of its £7,500 target.
On the fundraiser, it describes Luna as a "sassy little heart warrior".
Aimee says the money will go towards the funeral and ease any other financial burdens.
"Luna was loved by so many, but no one more than her devoted, strong mummy Jess," she explained.
"Now Jess is left with the heartbreak of losing her child while having to navigate the next steps."
If you'd like to contribute, please click here.
Aimee added: "I think the fundraiser shows just how many people Luna touched in her life.
"Luna will be so sadly missed. All of us are heartbroken."