The animal was shot dead by police officers after it attacked them as they tried to administer CPR to the woman, authorities said on Wednesday.
The woman succumbed to her injuries at the scene.
A man who was visiting the house is being treated in hospital for bite wound in the leg sustained in the rampage, police said.
The incident has prompted calls locally to re-examine laws on pets. Authorities said the dog had attacked before.
"This is a very tragic event for the family and our thoughts go out to them," said police Supt Tony Crocker.
"What a horrific incident."
The city had 389 reported dog attacks last year, the Canberra Times reported. Lawmakers are expected to debate introducing new legislation, such as stricter penalties for owners, in the coming weeks.