A caller reported the blaze had reignited at 10:28 p.m., a Washington County 911 dispatcher said.
Despite initial reports, the resident, who was not identified by firefighters, was not entrapped in the home, Fire Hose Co. of Boonsboro Assistant Chief Curt Fales said.
"When I got here, she was out of the house, and the fire basically ventilated itself through the rear windows of the structure," he said.
The fire destroyed the kitchen, living room and garage of the home, Fales said. Bedrooms and a finished basement sustained water and heat damage, Fales said.
The resident, who later was identified by family members as Jeannie Harsh, and two firefighters - Richard Brown and Capt. Pat Warner - were taken to Washington County Hospital for treatment of nonlife-threatening injuries, a First Hose Co. of Boonsboro spokesman said late Wednesday evening.
The spokesman said the woman initially refused to go to the hospital, but eventually was taken there.
A Washington County Hospital spokeswoman said she did not have Harsh listed in the hospital's computer records.
Firefighters said Brown had a shoulder injury and Warner had hand lacerations.
The hospital spokeswoman said Brown was treated and released, and Warner was being treated late Wednesday in the emergency room. The spokeswoman said his condition was not available.
Susan Harsh said her mother, Jeannie Harsh, was the woman inside the home at the time of the fire. She said her mother was not seriously injured as a result of the incident but was upset.
"She's pretty devastated right now," Susan Harsh said.
Susan Harsh said she had grown up in the home, and that her mother lived there for at least 25 years.
Susan Harsh and family members watched as firefighters continued to douse items inside the home and discussed whether they should take Jeannie Harsh to the hospital for treatment of respiratory problems.
Other family members worked to remove items from a finished basement.
Inside the gutted garage were remnants of the blaze - broken glass, soaked and charred rugs rolled up on the floor, a soot-covered Toyota Camry and a refrigerator covered with melted goo.