When someone dies without a Will, then this is called an intestate estate.

On our website, you will find an Intestate Distribution of Estate summary which will give you an idea of how an intestate estate is distributed.

You would need to read Section 14 of the Administration Act 1903 to get a full understanding.

http://www.austlii.edu.au/au/legis/wa/consol_act/aa1903173/s14.html