mugs on Family Tree Circles

I'm searching for information on my grandmother Dulcie Carter who was born in Lismore NSW Australia and Married John Mulligan. They had 12 children. My fathers name is Raymond Edward Mulligan and my mothers name is Carol Smith (maiden name). My grandmother had a twin sister Dorothy and there was 18 children in their family. My grandmother was also Aboriginal. I know that my father was born in Norwa NSW and my mother in Parramatta NSW and they married in 1975. I have a brother from this marriage Shane Mulligan and a half brother Adam Shelton from my mothers second marriage. I'm trying to find out more about my Aboriginal Heritage.

Thank you
Jared Raymond Mulligan
Born: 13/5/1980 at Penrith.