I don't know, I guess this has just been on my mind for a while now. I'm praying that whatever happens, its not enough to make my worst fears come true.
I know it's just a guess, but I'm sure that you know your mother enough to make very educated guesses. My question is, how is her life outside the JWs? What has she replaced the time and energy she used to spend with the JWs with? It may not be the believes what she misses, bit other things, from something to do, to friends, a sense of community, a sense of belonging, etc. Has she gotten that outside?
Something else to consider is that some people leave the JWs but have several degrees of believes. One example is yourself. You are still a Christian, which means that you still have some believes that may or may not coincide with the Wt's nonsense.
Something else to consider is just inquiring. Have you two have a conversation about it? How has the communication between the family members been about the Wt and their things. With your post I have the impression that every member in the family made their decision but never talked about it with the other (I may be wrong, of course). Is that a possibility, to just ask her?
I hope this helps.