Justin Anthony, the girl’s cousin, said she had no pre-existing conditions and hadn’t recently travelled to any foreign country, according to The Daily Mail.
Mr Anthony said she was placed on a ventilator at Children’s Healthcare of Atlanta-Scottish Rite Hospital.
She is currently still at the hospital listed in a stable condition.
The hospital confirmed that a patient tested positive for COVID-19.
Officials declined to go into details, however.
A hospital spokesperson told CNN: “The patient remains in isolation, and we have consistently used appropriate precautions.
“Additional details will not be released due to patient privacy laws.”
Mr Anthony told CNN that his cousin’s mother approved of him telling her story to the media.
The girl’s uncle Damian Anthony put out a plea from the young to pray for the child.
He posted on Facebook yesterday: “I have sad news to tell you.
“My niece Emma has contracted the CV.
“My sister asks you to pray for our family, yours and the rest of the world.”
Meanwhile, an unnamed 18-year-old Briton became the youngest person to die from the virus in the UK over the weekend.
the death brings a dramatic shift in the age range of patients, spanning 18 and 102-years-old.
All the deaths so far have were in vulnerable groups with underlying health conditions.
In England, 37 more people who tested positive for COVID-19 have died.
The total number of confirmed deaths there now stands at 257.
Nationwide, the UK has seen an increase in infections by 635, bringing the total to 5,683, the Department of Health said.