Ok, so we know you are looking at an agreement for a lesbian couple and that you do not live in Western Australia. That means your agreement would come under Part VIIIAB of the Family Law Act.
PART VIIIAB allows same-sex de facto couples to can make a binding agreement that spells out how the partners wish to deal with their property and debts should the relationship come to an end.
You can make a financial agreement before, during or after the relationship. What stage are you at?