Ellie Newitt, now 16, was diagnosed with acute lymphoblastic leukaemia in 2014, and during chemotherapy treatment she suffered a series of seizures and bleeds on the brain.
At one stage, surgeons prepared the family to say their goodbyes and readied a death certificate as Ellie wasn't expected to survive the next half hour.
Miraculously the brave teenager from Blaxton battled back from the brink and, after a chance encounter with Afghanistan veteran Ben Parkinson, was inspired to make a full recovery.
She has since undergone numerous hours of physiotherapy, completed seven GCSEs and is now off to Doncaster College and University Centre to pursue her dreams of becoming a primary school teacher.
And she was delighted to attend her Hayfield School prom accompanied by proud Ben, the most seriously injured soldier to survive the Afghanistan war, who was wearing his uniform and medals.
Her mum Marie, 35, said: "She felt like a princess, she said her dress was so pretty. And she said Ben looked handsome too, she had a fabulous time."
"To go through what she has gone through, I never thought I'd see her go to prom. It was amazing."
Ellie was a typical 12-year-old schoolgirl, when her family were hit with the devastating cancer diagnosis.
She suffered a series of complications and at one time had 16 fits in 24 hours which left her paralysed from the neck down and also resulted in her losing her speech.
She also has had surgery to fit a metal plate in her head.
During everything, Marie and Ellie's dad Darren, 41, rallied friends and family, including her 11-year-old brother Ashton, to encourage Ellie to fight back, and eventually she did.
Marie said: "She is an incredible fighter. We had been told she was in a vegetative state and were asked to consider switching off her life support.
“But slowly she started to breathe by herself.
”Her recovery has been a miracle. She has been in cancer remission for a years. Now mentally she is fine – but she is still battling to walk again. She is determined to succeed.
"18 months ago she was at the local leisure centre with my mum, and they saw Ben there with his physiotherapist.
"My mum asked his physiotherapist Robert Shepherd for advice, and after hearing her story Ben told him 'you have to help her'.
"Since then he has been helping her with physiotherapy and Ben has been an inspiration because of all he has achieved.
"He told Ellie he would be her date at the school prom to encourage her and he has been true to his word."
"I shed a tear when I saw Ben waiting for her in uniform and giving her a corsage. He is remarkable. All the other pupils were cheering.
Marie's parents have worked tirelessly to help Ellie through rehab and now Marie, a recruitment firm boss, says that mentally Ellie is back to normal, and can talk but can't stand up so still has a long way to go.
She attended the prom at the Mount Pleasant Hotel in Doncaster on Wednesday July 4, and looked stunning in a blue 'princess' dress donated by local shop Flutterby Bridal Boutique as a prize for the most inspirational teenager in the town.
She was also transported free of charge by ABC Flannigan Taxis Doncaster, who decorated the car so she could arrive in style.
Her next goal is to be able to walk down the aisle as Maid of honour on May 4 next year, when Marie marries her partner John.
Whilst serving in Afghanistant in 2006 Ben was horrifically injured after his vehicle drove over a landmine in Helmand Province.
He lost both his legs in the accident, suffered a broken back and brain damage.
But he fought back to walk again on artificial legs and carried the 2012 Olympic flame through Doncaster.
He has completed a number of long-distance challenges, including an epic 120km Arctic kayaking challenge and is due to take part in a challenge to tandem cycle the 1500 mile length of New Zealand later this year - using his hands to pedal a special bike.