Hello Verenda,
I know someone already said it, but you are among friends. people here think differently and coexist for the sake of support and learning. And isn't that all just kind of the point really?
First, the sheep and goats thing hasn't changed since the 90's. And to clarify what you think they believe (it is a twisted mess so don't feel bad), they still believe once the GT starts, it will be too late to repent, and you will have already been judged. Thats tribulation....not Armagedon.
If I was you, as painful and odd as it may sound, I would get up to date on all of this stuff. Get to the scriptures that basically say truth does not change. On one hand it can seem admirable that the society is willing to change when they are wrong.......but that isn't really what this is. its what everyone THINKS it is, but it isn't really.
The logical inconsistancies are good to be aware of when you hit a brick road like the one you described. Can they change their mind because they are imperfect men? Sure why not. Everyone misunderstands the bible sometimes even the apostles right? She is actually right. What she is not taking into consideration, is that if you do not agree with a "current understanding" or you "question the slave", you can be disfellowshipped. Imagine that, simply for thinking different and talking to maybe a couple friends openly....you could be DF'd.
Blood is a great one. You take Albumin for a medical issue in 1999, you are disfellowshipped unless you repent. A year later, its all good. Do they seek out ones mistreated by "former understandings"? Nope. There is a good one to explain.
Then with the new change, white blood cells are forbidden, and Abumin is "christian to decide". Yes Albumin is 6% of your blood, and white cells are 2.3% (rough). So what made these non-doctor type dudes decide one was a conscience matter, and one was not?
Leave her with questions. You are in a unique situation where you may be able to reach your family, but you need to be very careful and tread lightly.