The body of an elderly woman lay in a home in Sydney's north-west for several months while her daughter stole money from her bank account, police allege.

The 48-year-old daughter was arrested at a hotel in The Rocks on Thursday and was charged with failing to report the death of her 83-year-old mother and dishonestly obtaining a financial advantage by deception.

Melissa Peacock, whose mother's body was found in a bedroom at their Kellyville home. Credit:NSW Police

Police were called to the home on Alessandra Drive in Kellyville on Friday afternoon last week after a real estate agent found the body of the elderly woman lying in a bedroom.

There were no visible signs of injury on her body, police said.