Dear Tincx
I have recent (and painful) experience of this very point, though I managed to sort it out in the end, and so I wish you the very best with it.
As far as butturances of Support are concerned, DIMIA-Centrelink do not require that a family relationship should subsist between the parties. I read somewhere recently that there are rich Australian citizens who are willing to provide AoS's to complete strangers. Plainly, it is a commercial arrangement of some sort, which implies profit, but I gather that some people do get involved with them. I have no other information about this bit, since we have not had to investigate the possibility ourselves, but from what I read, the idea appears to be real, presumably because of the profit to the butturer.
I think that, however, the Balance of Family Test could have the potential to trip things up in the context of your family. One has to be extremely cautious about this Test, because it has tripped my own family up once, and I will kill it if it happens again, after all the hbuttle I've had to go to in order to sort it out!
For your mother, the Test might be quite simple. As long as she herself has no step-children, then only you and your sister would count in relation to her.
For your father and his partner, it would be vastly more complex, because all 5 children of the union would be counted in relation to both of them, so it would depend on where all five of the (hypothetical) "joint children" reside. This fact might prevent your father and his partner from being able to migrate together, ever.
Gil
--
