You know, I so rarely come across any negativity at all regarding my family and the fact I'm so young (I'm 25)... I'm almost always so positive about my large family, and the fact I love it the way it is, and my kids are always dressed well, clean and obviousely well fed and healthy. There's very little people can actually comment on!
And if anyone says anything to me, I always turn it around so the conversation is pleasant or positive...
I have only had a few negative comments from ignorant and rude people... I normally answer back with a rebuttal or sarcasm. I've only once or twice been downright nasty back and that was because they said whatever it was in front of my children. I remember once telling one lady it was a damn good thing she didn't have as many children as I do, because she obviousely can't handle and didn't care for the two she had... As we were walking away my DS1 just looked at me and said something along the lines of "we're so lucky that everyone in our family loves each other, aren't we"... It made my heart smile, although I have since tried not to lose my cool like that in front of my children again as I don't think it's nice for them to see.