Tilly, 11, lost both hands after developing Group B meningococcal septicaemia in 2007.
Since Tilly has travelled the world raising awareness of the complications that can follow meningitis, and fundraising for her own prosthetic hands – which can cost up to £20,000 a set.
Now almost 10 years later, the determination that saw Tilly survive against the odds has seen her team up with some of the world”s top scientists to make sure the next generation of prosthetic limbs are designed with the active life of a child in mind.
Tilly, of Consett, County Durham, hasn”t received her own arms just yet but is helping to test the life-changing limbs.
She said: “When I first started using these hands they were basically just these little hooks and you used them like a puppet to make them move.
“Now I”m working with a company called Open Bionics and they have made me a superhero arm – you can do these great poses with them.
“You can give a thumbs up. It is really cool.
“Personally I like looking like a superhero. I like looking unique.“
The revolutionary hands are made using 3D printing technology sent out to people in the post, which makes the products quicker to design and keeps the cost for the amputee low.
But despite her making appearances at ComicCon in San Diego, California, and a technology summit in Holland, the cutting edge technology has not followed Tilly back to St Mary”s Primary School in Consett just yet.
Tilly”s mother Sarah hopes with her feedback, the prosthetics will soon be out of the lab and ready to use in her daughter”s everyday life.
The 37-year-old mother-of-four said: “When she is wearing them she tells the scientists if it is too hot, if it is digging into her arm.
“If she is asking for them to be taken off regularly it probably means they are too heavy.
“It is really helping them – they need to work with the kids who are going to be wearing them.
“They can”t feel how it works and how it”s used by an 11-year-old. That is where Tilly comes in.”
But even without a new bionic hand to help her in daily life, Tilly is determined to do things on her own.
She has worked out how to do most things, from painting and drawing to opening a satsuma.
But the modern-day Tilly is a far cry from the young 17-month-old who almost lost her life.
Her mother thinks it was a shot of penicillin delivered by paramedics on the way to hospital in Durham which kept her daughter alive long enough to get the care she needed.
“I remember she looked a bluey grey mottled colour and started to be sick, I grabbed her off my mum and ran to meet the ambulance coming up the street,” said Mrs Lockey.
“I felt so helpless like there was nothing I could do to stop this.”
But between transatlantic trips and life-saving fundraising work, Tilly is still a normal girl who dreams of becoming an actress.
“I love art. I listen to music a lot. I do drama, singing and dancing,” she said.
And her love of superheroes doesn”t reach as far as a Halloween costume.
“I might go as Satan,” Tilly said, “I like to be weird.”