Unfortunately the passion of youth runs hand in hand with the black and white nature of their beliefs and a distinct lack in wisdom and experience, yet a strong desire to voice their opinion on what little they have actually been educated on. You ran headlong into that whirlwind it appears.

You are just wearing a kilt for your own expression of whatever it is you want to express, out with some other kilted friends who have something similar they want to express---she should not want to get a piggy back ride off of that for her own agenda. Cut her from your invite list and let her know why ("Geez, sister, you are really putting a wet blanket on the fun when you say things like that" usually works) and suggest that she find her own forum or gathering of spirits kindred to her ideas and not to yours to express her feeling and agenda in.