The family, along with their pet Chihuahua, was among 42 people sleeping on cots Sunday night at Bearden High School after a train carrying 10,600 gallons of the hazardous chemical derailed in the Farragut community near Knoxville.
No one was seriously injured, but at least 3,000 people were evacuated.
Perkins' husband, John, stayed behind.
"I kept calling my husband, trying to get him to come up here, and he said 'if I'm going to go, I'm going to go,"' she said. "My main concern was the kids.
"I told my husband, 'if you're going to be stubborn, stay here. But I have to make sure these kids get to safety."'
The train was traveling from Knoxville to Birmingham, Ala., when the accident occurred, said Susan Terpay, spokeswoman for Virginia-based Norfolk Southern railways, which owns the train and track.
Twenty-four cars of the 141-car train left the track, she said. The cause remains under investigation.
The highly corrosive acid, used in manufacturing, was transported as a liquid, but became a gas upon release.
Residents living in 20 subdivisions within about a mile of the derailment were asked to leave their homes.
Knox County Sheriff Tim Hutchison said it would be at least Monday night — and possibly Tuesday — before residents will be able to return home.
"It is just a slow, tedious process," he said. "There's a lot of liquid down there. It is fuming and it is very dangerous. ... We are all just going to have to bear with it."
Twenty people and one emergency worker complained of minor skin and lung irritation and were taken to a hospital, where they were treated and released, said Lt. Jeff Devlin, a member of the Knoxville Special Hazards Team.
About half a dozen schools in the area were canceled Monday as a precaution.
Gas continued to spew from the tanker Sunday night. Emergency workers were using water, foam, and lime and soda to neutralize the spill.