I would have been annoyed, it was rude of her.
I would never say that my DC won't eat anything when we are guests in someone's house, because it is rude, and because I always hope that the social/peer pressure, different environment etc means that they will eat it, even if they don't at home.
It often works, and they have eaten - or at least tried a small taste of things at school or at other people's houses that they wouldn't ever touch at home.
They do know it is OK to say No Thank you politely to things they really don't like, or to ask for just a tiny bit. Absolutely no rude remarks though, and that goes for at home as well as elsewhere.
Speaking about likes and dislikes before anything has been cooked is one thing, making remarks about something that someone has already been to an effort to cook isn't OK at all, and I want my children to learn that.