If the paperwork is involved and concerns legal/financial issues, is it possible to get a family attorney/accountant to deal with it? That way you won't be dragged into the drama every five minutes when yet ANOTHER piece of paper needs tending to. You can just cite illness as a reason for getting the attorney if they needle you.
Knowledge is power. You've got them figured out. They may get you down, but now they can't keep you there.
You go girl!