Something you might try with those "old" siblings. Send each of them a note telling them that you will no longer communicate with them about your mother's condition. They'll have to deal directly with the doctors, etc. (probably no one will tell them anything). If they call be very polite and tell them you will not longer talk to them on the phone and from then on if they call just say "I have nothing to say" and hang up. They'll get the message if you stick to it. Whatever you do, don't let them and their attitudes disrupt your own home and family. You'll have to be firm, have to mean it and have to stick to it. Ain't family grand ? HAH!
Pomaikai (Hawaiian for good luck), Judi