Re: Please...need advice!
Oh dear. My sympathy first off. I would go in and say hello and give her a big hug and say Hi Grand mother! Or whatever you call her. You can ask her if she remembers you. She probably won't.
Treat her like you would treat anybody that is elderly that you haven't seen in 12 years. If you have children, show her pictures. Chat about your life, what you are doing, what your life is like, how does she feel, etc. Chances are that if she is real bad you won't have much of a conversation. You may just end up taking a walk with her or just holding her hand. Is someone who sees her alot going with you? How do they say she is doing? that is always a help if you have some idea what her mental state is...
The best you can do is just to go in with a cheery attitude and play it by ear. I wouldn't plan too much. If she is in the later stages, don't be startled by how little response you may get, or the strange conversation you may have. She may be living 20,30 40 years in the past. Or she may think that you are her sister or mother. You never know. Just keep an open mind and go with the flow. It's the best you can do.
Is there some special little treat that she has always liked that you can take with for her? Or a little flower or two. Sometimes little things like that brighten their day.
Don't worry about the future-enjoy the visit with her and be thankful to see her rather than think about her not remembering that you have been to visit. Instead think that you have brightened both her and your day.