It's not a theory, it's my practice. There's many cultures/religions where drinking is not allowed and somehow they manage to socialise too. I just say "thank you, but no thank you, I don't drink" and that's the end of it, the one time somebody was pushy I just remarked I'm on medication (little white lie there) and that was it.
Plus, incidentally, this is Malaysia... I lived in Malaysia for several years in the mid 2000s. There's a lot of heavy social drinking there but there's also a predominant Muslim culture (the Malays) who in theory should be barred from imbibing alcohol. As such, Malaysians are, in my experience, very adept at mixing in social situations where copious drinking is occurring while still allowing for some members that abstain from doing so on cultural grounds not to fell out of place.
It isn't impossible to do. It isn't even difficult to do. In fact it's an absolute non-issue.
Now, this is not terribly relevant in the present context (this was her house, I presume the alcohol was taken from her drinks cabinet, & cetera) but you should never allow anybody to pressure you into drinking because of social pressure. That somehow you seem to believe that the social situation begets the behaviour is a bit alarming.