I am very sorry to hear that you are being disfellowshipped, I know how painful it can be.
Whether parents continue to shun seems to vary quite a bit. It's a very difficult thing to shun a child, no parent wants to do that. Very hardcore JWs do shun of course, they believe it's the only chance for their child to gain eternal life. At the other end of the spectrum you have parents who treat their children like nothing happened. Most parents are somewhere in the middle, often you have a kind of hot and cold, they miss you and then allow contact, but then the Watchtower comes out with a guilt inducing article and they go back to the hardcore shun for a while. It can be crazy making, try not to let it affect you to much one way or the other.
You know her best, but even so It's impossible to predict what will happen, so I suggest you prepare yourself for the possibility that she will cut off contact. This will be very difficult, there is no getting around it, but try not to take it personally, if she does shun you it is not because she doesn't love you, but only because she is being manipulated by a heartless organization. Let her know that you love her and will always be available to her. At least you have the hope she might someday see the organization for what it is, and even if not she may soften her stance as time goes by.
Sometimes peace comes with acceptance of things that are outside of our control, and this is one of those situations. If your mom passed away you would eventually come to terms with it and move on in your life, at least with this situation you have hope that she may eventually come around, who knows, maybe she will find ttatt on her own. Try to build up a network of friends to rely on so that you will be OK no matter what.
I highly recommend meditation for dealing with difficult situations like this, it has been life changing for me. It is easy to do, costs nothing and has proven health benefits as well. Another coping strategy is to journal, just sit down every day and write a few pages of your thoughts. No editing, just stream of consciousness, whatever pops into your head. There is something about the process that helps to you deal with things, you will be amazed how well it works.
Again, I am so sorry you have to deal with this ((hugs)). You are young and have your whole (cult free) life ahead of you, I am sure you will be just fine.