Minimus:
Sorry to hear about the friction in your family. It's the same story for all (or most) of us. Names and places differ, but the issues are all too familiar.
One point - doesn't the WT law concerning DFd or DAd people make allowance for contact concerning family matters? My family skates by all the time on that one. What I mean is, they basically do what they want with DFd or DAd family, and no one in the Hall can call them out on it, because they say 'Well, this is a family matter.' And that's the end of it.
I guess my point is, for family disposed to the notion, there remains a WT legal loophole of sorts for family contact. Maybe you could do the research for her, provide the quotes from the literature that proves this point, and let her have that ammo against hostile sis. I mean, your aunt would have to respect the fact that these words came from the Tower, right?!
Let us know how this goes for you. In a way, I envy those who left this cult and who were ultimately strong enough to do what they had to, and move on totally without the people that they loved. In the end, maybe it's easier that way then for the rest of us who try to pitifully hold on to whatever sense of normal that wicked cult allows for our families within.
This is a nightmare, and I used to be so scared. As time moves on, I become less scared and more and more angry. These days, I'm angry as hell. Religion is poison.