I'd just have asked her to continue talking about the sulphites in the wine because it sounds fascinating. So I'd have probably discussed a lot of biochemistry with her for hours because I'm actually interested in and have studied those subjects in far too much detail. I'd forget her bad comment and we'd just discuss the molecular structure and preservatives in the wine over a glass of tap-water.
I'd have just laughed the whole thing off and been grateful that anyone was taking the trouble to talk to me at all and invite me in.
I'd have laughed because she reminds me of several people, family and friends I've known and loved a lot who genuinely mean no harm at all, but just can't keep things to themselves and need to know everyone else's business. They still have lots of friends and they've been successful though. Others just learn to deal with them. She is mild compared to some of those people, really mild.
Some people I've known have said:
"I'm the bestest! I'm super me. Look at what I've done! This'll show them! I'm so wonderful."
Hence, I'm very used to behaviour like this so it really doesn't bother me.
Without awkward people like this, life would be very boring and lonely for me indeed!
I find this kind of subversiveness wonderfully refreshing. I guess it's because I'm so used to close some relatives/friends talking like this all the time. I could appreciate why other people might find those people irritating and downright intrusive, but I've had to cope with it for most of my life! If I say something to these people I never hear the end of it: the solution? Don't say anything that might be used against you in the future!
Frankly, aside from ruining the dress and her talking about diseases I'd never catch, but would read about in textbooks I don't see exactly what's wrong with her. I see no deliberate malicious intent in her at all. If there had have been I would have been out of that door. She reminds me so much of a few people that I have to see/live with on a regular basis that I would have tactfully forgiven her: I'm too soft for my own good I know.
In situations like this it's just best to be good humoured and laugh it off because that's what I have to do in real life with real scatterbrains. No joke. I come from a background where brutal honesty is valued (in a comic way) so this skit doesn't seem strange to me at all, in fact it seems strangely familiar. Oh and all that other social stuff she talked about I'd never get involved with, ever.