An 18-year-old man and three-year-old boy escaped the blaze at the property in White Strand View uninjured.
Gardai are investigating the cause of the fire, which is understood to have started in an upstairs bedroom.
Officers and firefighters were called to the house in the Aylesbury Park area around 9.20pm last night.
The woman was pronounced dead at the scene.
The property has been sealed off for forensic examination and the coroner has been notified of the woman's death.
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