Adoption is a federal order. It is lifelong and not reversible. Adoption in the family is not advisable as it changes the child’s legal family connections. Grandmother b comes mother, her children- in this case the birth mother- becomes sibling of their birth child. See the difficulty here?
Guardianship orders are made in several states of Australia, expire when the child reaches 18 and are reversible. They do not change the family connections. This is the more desirable way within family. Seek urgent legal advise.
Good luck with this difficult situation.
Published 19th July 2019