What are the stages of Alzheimer's?

I would guess my Mom at about a 5? I have read about 7 stages of Alzheimers. I would guess my Mom at about a 5? but thought i would ask the group here. Mom still remembers me, but she sees me four days a week. Most days she can name most of her kids. She can name some of the grandkids on a regular basis but has a hard time pairing them with the parent. For instance she can name my sons, but not tell you who their Mom is. Is also forgetting what regular food items are such as chicken nuggets. She wanted her guitar, so I brought it to her and she didn't recognize it. I also went to a seminar on Validation therapy where they talk about not to use the "therapeutic lie" Not sure I agree on that one, Mom thinks she is in a small apartment and keeps saying she wants to get a bigger apartment. I simply tell her there are none available at the present time. Why upset her and tell her that she will not be moving anywhere? It does get old because she dwells on it, especially after talking to my sister.