It's the 23rd Century not the 19th, alcohol wouldn't be used as a "nerve tonic".
Well, I too would question the need to use alcohol - the DS9 episode "Paradise Lost" explicitly stated that Bolian tonic water had a calming effect on the nervous system.
Though I guess one could assume that, in the context in which we're discussing it, the person wishing to consume the beverage in question was simply using 'calm the nerves' as an excuse to consume some booze!
There are two (major) things wrong with the situation:
1) In a tough situation the women, who is still a trained professional, panics and completely shuts down. This ain't the 1950's and that stereotype was tired even then.
2) There are millions of lives at stake all over the sector, they even tell you the number but I can't remember and you have the time to run around to find something that works. I know something that works. A swift slap in the face and I'm not saying that to promote violence against women, but in a situation like this it'd force a person to focus and save millions of lives.
The nerve tonic is hilarious for use on your own toon (if its a female). As far is it in the story-line, it didn't really bother me that much maybe other cultures alcohol works to calm down humans. There are far bigger problems in the game than a woman using "nerve tonic".