Hi OP. This is such a hard position to be in. I think, first up, you need to approach with love and kindness. Your mum(?) will be embarrassed and also likely feeling that she NEEDS to keep drinking. You are going to be threatening her coping mechanism and she will feel forced to defend it at all costs. So, unfortunately, you need to be ready for the angry defensiveness that will probably come back at you.
If you can, approach her when she’s sober. Also, research the options and have them ready- find out when the next zoom as meeting is and offer to be their for it. Maybe find out what AA entails (The steps etc) and that it is full of other “normal” people who have The same issues.
You don’t need to label her with alcoholic. You don’t need to know anything more about what/how much she’s drinking.
Above all, be prepared that this is very unlikely to work. Sorry, I know you won’t want to hear that but lots of us have walked a similar path and know from experience. If she does accept help, great! If not, don’t be too despondent. Ultimately, getting well is her responsibility and absolutely not yours. Remember:
You didn’t Cause this,
You can’t Control this,
You can’t Cure this.
You need to be ready to detach and mentally walk away from the problem, even though you can carry on caring. This is too big a burden for you or anyone to carry. Have you heard of Alanon (they help family members of alcoholics) and Nacoa (for children-adults included- if alcoholics). They can help you and the one thing you can control here is your own reaction.
It’s a tough problem. Very best of luck!