This topic raises so many issues.

Basically, everyone handles alcohol differently. Yes, it could be the menopause that is changing how their body reacts due to metabolism or genes. Could be their personality, where they need a drink (or three!) to gain confidence. Or, a habit picked up from family or friends because it's considered the norm. Unfortunately, if you can't talk about it with them then there's little chance of persuading getting help.

Unfortunately, I have first-hand experience of this with sister-in-law. Not long after my brother introduced her, noticed personality changes when she had a glass in her hand. She's outgoing anyway, not averse to being very blunt and thinks she can say what she likes. Amazingly, by next morning she's sober enough to drive to work. An eye-opener was when I overheard her talking about going to Weight Watchers, quote "if I watch what I eat then I can drink more". So this evangelical attitude towards weight loss/healthier diet hides a more sinister motive. Last year, she struck out at me because of something innocuous I said to her. Yes, she'd been drinking. Hasn't spoken to me since the incident. Wonder how she would react if she knew her mother-in-law also said she was drunk.