The milestone is nothing short of a miracle for Demi-Leigh Mahon from Telford, who last week started heart treatment in the hope it will lead to a double lung transplant.
"We have never known if she was going to make her 16th because her condition is so rare, specialists haven't been able to diagnose her," said Demi-Leigh's mother Kerry Mahon, 39.
"The doctors say she is unique and are calling it Demi-Leigh syndrome because they've never seen another case. She's struggled with her health all her life. She's had numerous operations. She has a lung condition called bronchiectasis and for the last 12 months we have been under assessment at Great Ormond Street Hospital for a double lung transplant."
She added: "What she goes through day to day is unimaginable. She has three nebulisers, intravenous antibiotics, an implant in her chest so she can have medication through that.
"To be quite frank every Christmas and birthday it's just amazing how we've got there because the slightest cold or chest infection, because she's got no immune system, is life threatening."
Those touched by her story have pulled together to throw her a party today, ahead of her big day on Tuesday.
And she wants all the proceeds to go to charity the Make A Wish Foundation, which made it possible for her to go swimming with dolphins in Florida.
"She's struggled with her health all her life. She's had numerous operations," said her mother Kerry Mahon, 39, of Wellington Road. "She has a lung condition called bronchiectasis and for the last 12 months we have been under assessment at Great Ormond Street Hospital for a double lung transplant.
"She's had cataracts removed, she's got implants in her eyes, she's had numerous chest infections. What she goes through day to day is unimaginable. She has three nebulisers, intravenous antibiotics, an implant in her chest so she can have medication through that.
"Not long ago we were at four hospitals in one week. That's been our situation over the last 12 months.
"To be quite frank every Christmas and birthday it's just amazing how we've got there because the slightest cold or chest infection is life threatening because she's got no immune system.
"They've said even with the lung transplant her life expectancy would only be another seven to 10 years because they have to suppress the immune system."
But despite her troubles, Demi-Leigh, who lives with her mother and father Darren, 36, and brother Darrell, 19, just keeps on smiling.
"She just takes it all in her stride. Everybody who knows her falls in love with her instantly," said Mrs Mahon, who works part time at electricals factory Tamlex in Halesfield, Telford.
"She's very innocent and just doesn't understand why there's so much hate in the world.
"She's a beautiful young lady and we are so proud to be celebrating her 16th."
Demi-Leigh's health problems have meant she has missed out on lessons at Hadley Learning Community at Telford.
"She hasn't been to school for a year and a half and she really misses it," said Mrs Mahon. "We try to do what we can so she can have a bit of a social life.
"She goes to Walford & North Shropshire College in Shrewsbury where she cares for the animals on a Thursday.
"Everyone there says she's got such a fantastic way with the animals. They sense something about her.
"But it completely wears her out. Thursday, Friday, Saturday she just sleeps. We call her sleeping beauty because she sleeps for days to recharge her batteries."
Today will see Demi-Leigh celebrating in style, before she turns 16 on Tuesday.
"We just want to make her feel special, like a princess with all eyes on her," said Mrs Mahon.
"She will have a Limousine for her and five VIPs and she will be wearing a dress especially made by Celebrities in Cannock.
"The owner of Crush at the Vox in Telford has given us the venue and Dragon's Den next door is providing the food. Everyone has come together to help us do it for such a little cost It just makes us feel blessed."
Charity the Make A Wish Foundation made it possible for Demi-Leigh to go swimming with dolphins in Florida, in 2010.
"She had such a fantastic time, the memories are just unbelievable," said Mrs Mahon. "I was asking her what she would like for her birthday and she said I have been thinking, instead of everyone giving me a present, would they make a donation to the Make A Wish Foundation?
"It broke my heart. But that's her all over. She is just such a kind and giving young lady. It's a wonderful charity that made her wish come true and it would be lovely to be able to give something back."
And Mrs Mahon will literally jump at the chance to raise money for the same charity with a parachute jump for her 40th birthday.