Layla Grace Milsom was diagnosed with pectus carinatum, known as pigeon chest, in 2016.
The condition causes her sternum and rib cage to protrude outwards as she grows.
It gets worse as time goes on, but if Layla can get her hands on a special brace that isn’t available on the NHS she’ll be one step closer to achieving her dreams.
Her mother, Charlotte, from Llanharry, said Layla loves to dance and she fears the condition will stop her.
She said: “At first when I used to talk to people about her chest, they’d tell me not to worry.
“But when she started growing up I noticed it started to get worse and you could really see her chest protruding.
“After being examined, she was eventually diagnosed last year.”
Pectus carinatum effects one in every 1,500 children but there is treatment available for those who suffer with the condition.
Layla could have a specially custom-made chest brace, which would gently press against her sternum, to help reshape her chest as she grows.
The brace is more effective if it’s used at a young age so Charlotte hopes she’s able to get one soon.
Charlotte explained: “The only other treatment she can have is an operation when she’s 16.
“But I don’t want her to have the operation because it’s a very big procedure and it will take her a long time to recover.
“She loves dancing, and regularly goes to classes.
“I don’t want the condition to have an impact on her dreams and ambitions, because she loves to dance.”
Even though the condition hasn’t limited Layla physically yet, Charlotte says her chest is getting progressively worse.
She’s tried to explain to Layla how her chest is different to other people’s by asking her to compare it to her sister’s.
But Charlotte has also told the little one that people are “raising money with buckets” to try and get her better.
“We need to raise £3,000 and we’ve raised around £800 so far, which is really good,” Charlotte added.
“I just hope we can get her the brace.
“Everyone who has helped so far have been so generous.
“Thank you so much. Layla really appreciates it.”
To help support Layla, visit her fundraising page at www.gofundme.com/laylagrace5