I know exactly how she feels.
Three years after quitting drinking at the age of 27, I've accepted my role as the non-drinker at any given dinner party or social event. I'm happy with my decision to teetotal, but some of my peers are less so -- for example, my friend's roommate.
"So you're not drinking? At all? Really?"
I have never had alcohol, but I have never begrudged anyone else the choice to do so. Drink and drive? Yeah, that's dumb. I'll judge you for that. Drink until you puke and have a nasty hangover? I'm not going to feel sorry for you. But if someone wants to drink, that's their choice; I really don't care. So, I guess it puzzles me why me not drinking would make people uncomfortable.
It must be an insecurity thing. If people were completely comfortable with their decision to drink, then it wouldn't matter if someone else chose not to. Drinking alcohol is such a huge part of our culture that you would think there wouldn't be as much insecurity about it as there is.
The best comment (of all time!) in regard to me not drinking was a coworker years ago. "I'd respect you more if you drank." No comment necessary.