I think it is possible. But not EASY or happy. A couple of days ago, there was another thread about the question why some witnesses become inactive, even have "wordly" girlfriends/boyfriends, but still hang on to their former beliefs (blood, holidays, voting, etc.)....they have a belief structure that is partially JW beliefs and in part their new found ideas.....
I think that most JW went through a programming that was heavily pushed on them - think about the process: bible study (some guy sitting in your home, personally repeating the same ideas over and over again), than all the meetings, assemblies, literature.....
.....now, to the answer, how do you "reverse" that? It would take the same amount of effort, time. You would either need the same "machinery" working on you in the opposite direction OR you need to be a person with strong mental abilities to detect what is part of the programming and "un-programm" yourself. Most aren't in the latter position. Specially, most people that become JW aren't very strong in that (otherwise they couldn't have been deceived so easily), many had depressions (or still have) and are on the weaker side emotionally, so there you have it: trapped!
As for your mother, in order to give up her beliefs, she will need others to substitute. It's like somebody that needs to change his/her home/house, because the roof is leaking and the place is shabby, but can't move out into "the nothing"....there most be another house ready to move in, otherwise they won't do it. But if you don't have the money or energy=mental, spiritual, emotional energy to go and look for another place or even build a new one by yourself, than you're stuck to the present "home of thoughts/beliefs/faith" - and you know what? I have met people that KNOW they're in a shabby, humid, dirty place, but have become used to it and have so many memories attached to it, and are lazy to change their lives, that they prefer to just stay.
Trojan.