It happened on the 2600 of south Garth Avenue in the South Robertson neighborhood at around 11:20 a.m.
The woman was found in a bedroom in the back of the house. A few minutes later, firefighters arrived at the scene and contained the fire in about 20 minutes.
Firefighters had to use gas-powered rotary saws to cut through the windows to get inside.
"There were security bars," said Battalion Chief Alert Ward. "This is also a reminder for smoke detectors; we were unable to confirm if this building had smoke detectors."
The victim's family members, along with other loved ones, showed up at the home and were overcome with emotion after speaking with fire officials.
Arson officials are investigating the cause of the fire. The woman's identity has not been released.