Chalfant immediately ran to the home of a neighbor who called 911.
"She's pleading for quick, quick help. She's in severe pain," the caller told 911.
Chalfant is still at the hospital suffering from traumatic injuries, though authorities wouldn't describe the nature of her wounds out of respect for the woman's family.
Officials have begun searching for what's believed to be a black bear, though Florida Fish and Wildlife rep Karen Parker described the attack as unusual.
"Bears are very, very elusive," she told CNN. "They're pretty much more afraid of you than you are of them, and normally when they see a human and they've not been fed and have not been habituated -- they're going to run away. They don't want to encounter us any more than we want to encounter them."
"There were no witnesses to the attack, and we have not been able to speak to (the victim) yet, so we don't know exactly what happened," she said.
On Tuesday night, authorities captured a female yearling bear, though they don't believe it's responsible for the attack on Chalfant. They will use the young bear's DNA to help with the investigation.
"Catching a bear is a difficult task and we're going to do the best we can to make sure it's all squared away," wildlife official Mike Orlando said.
There are about 3,000 black bears in Florida, where several bear attacks have been reported in the last few years. They are a protected species, so it's illegal to hunt or feet them.