At what point in dementia decline am I in when my wife at times will absolutely think I am her brother?

starting of ALZ... my mom thoght I was her sister.

WHEN I CORRECTED HER, THAT WAS THE LAST DAY SHE SPOKE. :(

So, do not correct her, it really doesn't matter at this point. My mom lost one more way to communicate. Not many other options left.. glazed stares, hoping to get a glimpse of a reaction.. not good.

My Mom is 91 with Alz's and she is going thru this thing where I can't keep long pants on her. I have her wearing disposable underwear and long tops so that they hang down far enough when she takes off her pants then she's covered some what. I've read something on here about pacing...she does it all day....no sooner her rear end hits her chair, she stands up and walks back to her bedroom. She will lay down during the day and take naps but if it's real late and I tell her to go to bed she says she can't lay down to sleep cause she can't breathe yet she does it during the day...it's only when I want her to go to bed so I can get some rest that she says this....I am really burned out as she is almost deaf and you have to yell anything you want her to know or to answer her questions. I have a device with headphones that she can hear with but with her constant pacing...you have to take the headphones off her just about the time she puts them on. My older brother has her financial poa and Mom pays all the bills and I think my brother thinks cause we are living here free, me an my son, that we don't need any help...my younger brother visits her about once a week and brings her her favorite hamburgers but my older brother, the poa never darkens the door and I just don't understand how he can do me this way...if I ask for them to keep her so we can get some respite he has to check his calendar to see if they can do it. I'm sorry, when I started this I didn't mean for it to become a rant. I know if we put her in a nursing home the strange surroundings and people will kill what little mind she has left. She has two way conversations with people who aren't there providing the voice for both..she will also . do this with her stuffed animals plus the nursing home would take her home which is completely paid for. Again sorry, just needed to vent. OOPS...ranted on the answer page.

You're in the stage where she thinks you're her brother, that's all. Different thing happen to different people at different times. It isn't indicative that she's near the end or of anything else other than her disease is progressing.

There are 70 different types of dementia, so as you can imagine, they all behave differently. Don't concern yourself with where in the journey you and your wife are, because it doesn't really matter. The best thing to do is go with her lead, so if she thinks you're her brother, go with it. Don't argue with her about who you are, because she doesn't control what she understands. Her brain is a little broken.

My mom confuses me with her sister, and if I mention my dad, she thinks I'm talking about her dad. It's as though her 66 years of marriage completely disappeared, and it's absolutely heartbreaking. Still, she's there and she's interacting with me, so I just put the sadness aside and let her lead the conversation.

Check the Alzheimer's Association website for a lot of good information on how to deal with your loved one. www.Alz.org

It can be at any point early or late.
If her brother had dark hair and you have dark hair that might be enough.
If you have a nose in the middle of your face and he did as well...that might make her think you look like her brother.
If her brother wore pants....you get the idea.
If she is in the mindset that you are her brother...play along as long as it is not harmful or does not bring back bad memories.
If it is bothersome to her, upsetting to her then try to redirect her focus at the moment.
If it bothers you and if it is something that you can not deal with I hate to tell you this may continue for a very long time and this is possibly one of the less bothersome aspects of dealing with dementia. You get used to it or decide that at some point you might have to either get help in that will be able to care for her or you begin looking for a Memory Care facility.
My Husband used to follow different people in the store thinking they were me. I used to say when he was following someone in their 20's with long hair that was me when we met, if he followed someone a bit older, heavier and shorter hair that was me in my 40's if he followed a gray haired old man that was me in my 60's! Sometimes ya just gotta laugh,a sense of humor can go a LONG way in dealing with dementia!