Police were called to a home in Beachcomber Avenue at about 3.30pm on Sunday after neighbours heard people fighting and someone screaming.
It is believed a man armed with a cricket bat has bashed the woman to death and knocked another man out.
The victim is believed to be Tina Kontozis. Ms Kontozis worked at the local long day care centre Goanna Patch Kindergarten and has written a book about Bundeena.
The offender is believed to be her husband and the injured man her son.
The offender has not yet been apprehended and police officers are currently at the entry point to the suburb on Bundeena Drive.
While there is only one road in and out of the village, police are concerned the offender could escape on foot via the Royal National Park.