What would you have said if you we're in my place?

I absolutely love your chosen nickname for this woman. She sounds ridiculous. I think you were very controlled in telling her she was rude and should leave and it was very much deserved. In fact, she should have appologized to the guest of honor, you know? But I am sure that is the last thing she would ever think of doing on her own. You didn't embarr her- she did a good job of embarring herself! If anything, to keep the peace, I'd sit down with some other moms and tell her how you feel about her militant approach to feeding. I understand thinking feeding is the way to go and that others should do it, but instead of acting like a bully, she could suggest it, offer her help to those willing to try it, and be encouraging. You did much better than I could have in the situation- I would have fussed that rude woman out!