You have certain rights that are being trampled all over – your question is, do you want to lose your accommodation by asserting them (as you probably will, one way or another).
I suspect your landlady is probably evading tax and is certainly playing fast and loose with Boarding House laws. Have a look a THIS FACTSHEET from Tenancy NSW and have a think about what that means to you.
Regarding the missing parcel, report it to the Post Office. They don’t have a valid signature which means it has been accepted fraudulently and when you have established that you can ask for it to be replaced.
You don’t have to blame the landlady – that’s up to you. But she didn’t need to accept the parcel and if she hadn’t you would have been able to collect it from your Post Office.
So report the missing parcel to the Post Office. And meanwhile I would be looking for somewhere acceptable to live that’s run along slightly more legitimate lines.