The hardest to respond to were "so what curriculum were you using at home?" and "what's so wrong with my kid if we're not being told she has to skip?" Since my gut reaction in both cases was sarcasm, I didn't say much to either question, which was probably best.
LOL-- indeed.
My answer when pressed on this point tends to launch into early childhood educational philosophies in GORY detail (leaving out the part where I was reading all of those research articles and books out of
desperation because my kid didn't seem to be doing the things she was SUPPOSED to be doing, and instead seemed to be doing things that were developmentally, well... impossible) ... which generally makes them Very Very Sorry That They Asked by the time their eyes glaze over.
I figure if they are rude and presumptuous enough to demand an answer there, I owe them nothing, and therefore it's totally not my fault if they feel a vague sense of crushing parental guilt for not doing more for their own kids.
But that's me. I've just learned that such conversations pretty much never go anywhere good either way. So it's that or say nothing at all, which is generally what I try first.