10 years ago I could (and did) drink a bottle all by myself. I also smoked like a chimney. I was in my 20s so could get away with it. These days, a bottle to myself would see me spending the night with my head down the toilet - though there's a good chance that I'd actually drink myself to sleep before finishing the bottle. These days, I prefer green tea, no longer smoke, and run five miles three times a week (though I don't need much pressure for my halo to slip
).
I know several people who could drink a bottle of wine without being drunk and incapable, or unable to function the next day because of a hangover. I don't think it necessarily signifies a dependency on or a problem with alcohol.
However, a whole bottle would definitely put strain on someone's liver. A typical 12% bottle is 9 units - well over half of your weekly unit allowance. You can argue to the cows come home about whether or not someone is a lush because they drink a bottle every saturday night (I don't) but you can't deny the health consequences of that. I think there are a lot of people out there with an alcohol 'problem' in the sense that it's damaging their long-term health even though there are no other negatives associated with their drinking.
The ability to drink a bottle in one go suggests it's a regular occurrence. Most people who drink 'sensibly' (i.e. sticking to around or under the recommended limit per week) could not manage a whole bottle.
Was the friend planning to stay in and drink the bottle all by herself with no company? I find that rather sad TBH - drinking a lot because you've got company and you're not keeping track of what you're consuming is one thing, but sitting in on your own and getting drunk just seems really lonely and pointless to me, but each to their own I guess. I suppose some people might say the same thing about me and my green tea
.
Ultimately, her body her choice. People abuse their bodies in all sorts of ways - by eating lots of foods high in trans fats or sugar, smoking, taking OTC painkillers too regularly, etc. They are the ones bearing the consequences, so I can't really see the point in getting shocked about it or judging.