Kali Hardig got violently ill just days after swimming at a water park in a lake near Little Rock.
Doctors diagnosed her with a rare meningitis caused by a parasite that thrives in warm fresh water.
The disease kills 99-percent of people who contract it.
"I've never even heard about it until Kali got it and then for me a mom, or a dad to be told that there's no cure for this amoeba is just heart wrenching," said Traci Hardig, Kali's mother.
"It's hard for us to even think about the possibility of a child even getting sick out here," said David Ratliff, owner, Willow Springs Water Park.
Kali is the second child to get sick at the same lake believed to be the source of the infection.
Three years ago, a 7-year-old boy died after swimming there.