The blaze broke out in the house at Mayollan Terrace, Coalisland, Co Tyrone in the earlier hours of Tuesday morning.
A man in his 50s, who was also in the house at the time, was treated in hospital for less serious injuries.
The family pet dog also died in the house fire.
Detectives ice said the cause of the fire had not yet been established, and inquiries were continuing.
The NIFRS said no smoke alarm had been fitted in the property.
Detectives have appealed for anyone with information to contact them on the 101 non emergency number.