Eighty years ago when Sheila Thorn was diagnosed with Type 1 diabetes as a baby, it was considered to be a fatal condition.
However, as she said herself, she was in the "right place at the right time" and ended up being treated by insulin pioneer Dr Frederick Banting.
Dr Banting immediately put Mrs Thorn, who at that time lived in Canada, on insulin injections and she lived a long life until her death last week.
Diabetes UK said that probably made her the longest-lived insulin-dependant diabetic.
Her funeral will be held at the Surrey and Sussex Crematorium in Crawley later.
Before the discovery of insulin, the only treatment for the high blood sugars - which result after insulin-producing cells in the pancreas fail - was a strict diet in which sugar intake was kept to a minimum.
At the most, this would give patients an extra few years of life, but many diabetics died of starvation due to the restricted diet.
Dr Banting and medical student Charles Best first kept a diabetic dog alive for 70 days by injecting it with a canine pancreas extract.
They conducted their first human experiment in 1922 on a diabetic 14-year-old boy who had been dying of starvation.
The insulin lowered his dangerously-high blood sugar levels and kept him alive.
"In those days, not many people knew anything about diabetes," said Mrs Thorn in an interview in January.
"So I say I was lucky because I was in the right place at the right time to have been treated by someone at the forefront of diabetes treatments."
When she was seven years old, Mrs Thorn's family moved from Canada to the UK and she became the first child to be treated by Dr Robin Lawrence at King's College Hospital in London.
"I don't know life without diabetes," she said in January.
"Growing up, I never let diabetes get in the way of anything.
"My mother was particularly keen for me to be a normal little girl and not be seen as an invalid."
'Long, happy lives'
Mrs Thorn, who previously lived in Tunbridge Wells, helped raise awareness of diabetes, and gave interviews on behalf of the charity, Diabetes UK.
Recently she said: "I've seen a lot of changes in the way people use insulin and these days I use an insulin pump to control my own condition.
"I'm thrilled to see that people with diabetes can live long and happy lives for generations to come thanks to this treatment."
Jill Steaton, from Diabetes UK, said: "She was a great asset in helping our charity raise awareness of the condition, our thoughts are with her family at this time."