The black and white cat, called Pippa, seems to be able to sense when diabetic Mia Jansa's blood sugar levels drop dangerously low, and is able to alert family members.
The Jansa family, from Whitstable, adopted Pippa from the RSPCA in August, after she had been abandoned in a cardboard box outside a shop in Dartford.
"We got her as a rescue cat for a family pet," said Mia's mum Laura. "She really was very gregarious and we bonded with her immediately."
But little did Laura and Mia know that soon Pippa would repay them for saving her.
Mia was diagnosed with type 1 diabetes at the age of six. If her blood sugar levels drop dangerously low she can experience a hypoglycemic episode, which could lead to a coma.
Laura and Mia learnt of Pippa's special ability when she crept into Mia's room one night and woke her up by walking over her arms and legs.
Once awake, Mia - who is prone to suffering hypoglycemic episodes in her sleep - decided to test her blood sugar levels and discovered they were dangerously low.
"We quickly realised she was warning us," said Laura. "If Mia didn't wake up, then she would come to my door and miaow.
"She comes onto the bed, walks onto my pillow and across me until I wake up. She really makes her presence felt, she won't take no for an answer. She knows it's important that I get up and help Mia."
Alice Potter, pet scientist at the RSPCA, said: "Although dogs alerting their owners to medical problems such as epilepsy, cancer and dangerously low blood pressure is well known, the RSPCA is not aware of any evidence in cats.
"Perhaps Pippa will be the cat to inspire new research in this area."
More on Parentdish