This has not happened yet, but it is the one thing I am most terrified about at this time. She has mistaken 2 of my children for 2 of my siblings, so I am starting to get extremely nervous that the day will come when I walk in to her room to start her day, and she won't know who I am.
It may never happen that mom doesn't recognize you. It's more common with Alzheimer's than the other dementias to forget loved ones faces. With all dementia, however, they do regress in time to different decades when they didn't have children, so that's a reason for forgetting who we are or not recognizing us. It constantly changes, too, so tomorrow can be a whole new scenario for mom than today was.
I hate dementia with everything in me. I pray you don't see your fear come true with your mom, and that she knows who you are forever. Best of luck.
However, sometimes it comes and goes, depending on the circumstances.
When my mom lived with me, she often thought that I was a nurse, a man, or the another "Andrea" (my name). She thought that she was in a nursing home, and that lots of other people were there.
Now, she is in a nursing home, and she recognizes me every time. It's because I visit often, and made it a point to talk to her and do things to keep her very engaged.
So what do you do if that time comes? You may have to re-introduce yourself every time you see her, which, because she lives with you, will be every day. Something like, “Good morning mom, I’m Jane, your daughter, how are you today?” Even that simple intro may cause problems. She may deny that you’re her daughter. In that case, distract her- offer to go for a short walk or get a drink. Don’t try to convince her otherwise. You may have to revert to simply saying, “Good morning, I’m Jane, how are you today?”. Don’t test her. Asking, “Don’t you remember me?”, or “Don't you know who I am?”, will put her on the spot and cause her embarrassment or anxiety.
Relate to her in a dignified way. I realize your mom is still living with you, but I read posts where the LO is in a care facility and no longer remembers their family. The family may ask, “Why should I visit, my mom no longer remembers or knows me”. This is missing the point. It’s no longer about the caregivers, it’s about the patient and the dignity of life, however, fleeting that may be. Although their LO no longer knows who they are, they, the family, knows who she is. They know the importance of their LO in their lives. That importance needs to be reflected in continued visits.
So keep your mom’s dignity in mind throughout this difficult journey. And touch is important. Holding hands and hugging will always show her that you care.
My wife was in memory care for many months and when I would visit I would merely say, “Good morning, honey, how are you today?” I never mentioned my name or our relationship. When I left I would always say, “I love you”, and she would reply, “I love you more!”. I don’t even know if she knew who I was! But I was someone to her.