Girl, 3, Caught the Flu. Two Weeks Later, She Was Fighting for Her Life with Sepsis

“You never think that your child will get that sick," Cordelia Stone said of her daughter Lydia's illness

NEED TO KNOW

• Cordelia Stone’s 3-year-old daughter, Lydia, was diagnosed with the flu and later developed pneumonia and invasive group A strep that led to sepsis
• Lydia underwent two surgeries to extract infected fluid around her lungs
• “You never think that your child will get that sick,” Cordelia said

A 3-year-old girl was diagnosed with the flu — and then it became much more.

Cordelia Stone, a mom of two in Sydney, was told by a doctor that her daughter, Lydia, just needed rest to recover from her influenza A diagnosis, according to nine.com.au. However, she had already spent a week at home with a fever.

Seeking advice from another doctor the next day, Cordelia was told, “Don't go home, don't even get clothes. You need to get to the hospital straight away.”

Lydia's illness worsened as she spent more than two weeks at Hornsby Hospital and then in intensive care at The Children's Hospital at Westmead. Her limbs swelled, her skin began to peel and her left lung collapsed, per nine.com.au.

She also developed pneumonia and invasive group A strep that led to sepsis.

The young girl underwent two surgeries to extract the infected fluid around her lungs.

“You never think that your child will get that sick," Cordelia told the outlet. "I would never wish it on anyone."

Lydia eventually made a full recovery, but about three months after being discharged from the hospital, her hair began falling out.

“Then it started coming out in clumps. The GP said that's quite a normal reaction after the body has experienced severe trauma,” Cordelia said.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

Reflecting on her daughter's severe illness, Cordelia said she “regrets” having been “too busy” to get her kids vaccinated.

“I have so much mom guilt over that,” she said, adding that the doctors at Westmead said that if Lydia had been vaccinated, “it's unlikely she would be here [in the hospital].”

“I will never miss a vaccination again,” the mom said.

PEOPLE reached out to The Children's Hospital at Westmead for additional information on Sunday, June 14, but did not receive an immediate response.

Last year, 4,256 children in Australia were hospitalized due to the flu, per nine.com.au.

More recently, the Commonwealth Scientific and Industrial Research Organization reported that a fast-moving influenza strain nicknamed "Super-K" has been spreading across Australia.

Children under the age of 5 are at increased risk for flu complications, as well as people over the age of 65, people who are pregnant and people who are immunocompromised, per the Australian Centre for Disease Control.

Common flu symptoms include fever, chills, a cough, a sore throat and a runny nose.

A few forms of protection against the flu are vaccination, staying home when you have symptoms, regularly washing your hands, improving ventilation indoors and wearing masks when around other people.