Hmmm, a real tuffy not knowing more about your mom personally. But I was brought "in" when my mom started studying when I was 8 so I can relate. I am now 53. I had no religious training before my mom became a JW, although my mom was a practicing Catholic before I was born and she had me baptized one. But when she got together with my father she stopped going. So I was pretty much raised in the "Truth" too.
I had lots of doubts over the years. You might focus on some of her past doubts to see if she says anything negative at all. I remember too, thinking my son would never make it to first grade in this system and now he is 33. I have three grandkids. The problem with doubts is that the Society has indoctrinated into its members the thinking that if you doubt it is something lacking in you so many that doubt don't talk about it. If they do others railroad them with how this is their fault and they need to study, pray, go out in the field more, etc. No one sits down and really discusses doubts. If you do then you are branded a rebel and marked.
Your mom has known nothing else. Even if she has some big doubts in her mind she lays the blame on herself, like all good JWs do when they doubt. She has even more reason to believe now because of loosing her sight and getting older. The Society offers a "cure all” for world problems, sickness and even death, but only if you stay active, and that is what attracts people to it and keeps them there.
When all the family is in, all your friends are in and some people work within the group and your social life is within it is hard to leave even when you know the facts about the Society. And to top it off, leaving is usually a long time process, the time depending on the individual and their needs and outside contact with the "world."
I would advice you to take it slow. See where she stands on some old doubts. Skillfully maneuver the conversations with a little doubt here and there and see how she feels. Bring up a few less intense things you have felt and see how she feels about them and about you having a few doubts.
Go slowly. As your own emotions are bouncing, imagine her feelings if she starts to really realize that the Society is false. She will have to deal with the facts like I did, that I wasted my whole life believing this crap and the fact that there now is not hope of a "cure all" for our health problems and what ever issues we deal with, and a whole lot more. The fantasyland that a JW lives is very real to them and to come away from that opens all sorts of life things to deal with like no cures for illness just around the corner and dying.
It took me several years to work a lot of stuff out. It was very hard at times. If she is strong emotionally that will help. If not, you need to get her some support. If not, she will block out the new information and revert back to the Societies thinking and indoctrination. It is very hard for the mind to readjust to new thinking when your mind doesn't know how to think. And most JWs don't know how to think since the Society tells them they should not think independently of the Society and Jehovah. And the followers believe that with their whole hearts.
BTW, as a 53 year old, I am now in college going into my second year this month. I have been on the Dean's list for the first year. I didn't think I could ever do it and it took an amount of time to get where I'm at. Your mom can do whatever she needs to also. You are right, she should go to school for the blind. Even as a JW she should. Encourage her to do this. It will build her confidence. It will make her less dependent on everyone including the JWs. It will get her somewhere the JW aren't. I would be good for her in so many ways.
I wish you and your mom the best and I am sure that others here will help you continue on your own journey of discovering who you are too. Keep moving forward, it is worth every minute of the journey ahead.
As Always,
Lindy