The 83-year-old woman was found dead on Friday in a bedroom of a home in Kellyville in Sydney’s north west, with no visible signs of injury.
Police were called to the house on Alessandra Drive after a real estate agent located Mrs Peacock at her home.
The woman’s 48-year-old-daughter, Melissa Peacock, has not been seen since Monday of last week.
Strike Force Youman, comprising detectives from The Hills Local Area Command, has been formed to investigate the death and also to locate Melissa Peacock.
Police hold serious concerns for her welfare as she has not been to work and all efforts to contact her have been unsuccessful.
The two women shared the house in Kellyville.