However, she can't always keep track of time and sometimes starts at noon, and by 4pm she is inebriated. I am afraid of her falling. I tried to talk to her about it and she just got mad and thought I was exaggerating the amount she drank. She is not an alcoholic and I try to keep her distracted but I am stressing about this. Any ideas?
As an aside: my father, a non-drinker most of his life, usually turned down a glass of wine whenever asked. However, if a glass was poured for him, he'd drink it, ask for more, and drink mine when his was gone (he had dementia). Apparently, as long as he didn't know it was wine, it was fine!
Depending on how far along your mom is in the disease, she probably would not realize that the wine she has access to is free of alcohol. I know my mom would not know the difference!
I would not try and stop her completely because it is something she can still enjoy. Let us know how you get on.
Since we lived together it was very easy for me to control how much he got. And since he was never going to have more than 2 glasses I decided not to worry about when he had them. A beer at 10:30 am was no better or worse for him than a beer at 3:30 pm, and timing was one less rule to impose on him.
When we went out for lunch at a German restaurant, he always had an imported beer. It made him feel "normal" and adult. He usually had wine if we went out for dinner. At home he might have a beer watching a ball game, or wine with a meal. But he never drank one beer after another all day long.
I wonder if it would help to have a "cocktail hour" before dinner? Maybe late afternoon stop and sit with her and have wine and crackers and cheese or sardines or radishes or some little nibbler. You drink wine or the beverage of your choice with her. If it becomes a nice little shared ritual it might be easier for her to accept "wait for cocktail hour" when she asks for wine.
If she prefers to help herself to wine instead of being served, limit the amount that is accessible to a reasonable day's worth. (For example, 2 glasses = 10 ounces.) Then whether she drinks it all between 12 and 12:30 or has a glass with lunch and one with dinner, it really won't matter.
I would not allow unlimited access to wine. And I would ask her doctor to set a reasonable daily limit, if that has not happened.