G.♣.
Please ignore Kristine. That was very rude. She shouldn't judge those of us who choose to know the gender before the birth.
I have two boys, and I don't remember anyone saying anything to me. Then again, if it wasn't that, it would be something else.
Pregnancy and the first couple of years are funny. Perfect strangers feel like they have the right to comment on everything.
I would just continue to smile and be polite. I would also be annoyed, but unless you want to practice a smart comeback, you'll just have to live with it.
ETA - Kristine, I'm sorry, too. My comment was way too harsh. I shouldn't have said anything at all.