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.
COMMENT RULES: Comments that are judged to be defamatory, abusive or in bad taste are not acceptable and contributors who consistently fall below certain criteria will be permanently blacklisted. The moderator will not enter into debate with individual contributors and the moderator’s decision is final. It is Belfast Telegraph policy to close comments on court cases, tribunals and active legal investigations. We may also close comments on articles which are being targeted for abuse. Problems with commenting? firstname.lastname@example.org