Amibu is there any chance whatsoever that you know you and your DP should have taken your child straight home regardless of how many times the host insisted you should go back to her home and taking your feelings of stress and frustration out on her (and others here) because you know you made the wrong choice?
I know it is hard to calm an overtired child, I really do. And I know it can be hard to keep saying no to someone who is insisting that you do something, especially if you don't want to appear rude. But if you thought at all that your son would be feeling this way then that's what you needed to do, say no and take him home. I know it's easy to say that with hindsight but I am wondering if that's why you are still so upset about her comment days later and why you are lashing out a bit at people here. Because you knew at the time you were doing the wrong thing, did it anyway while hoping for the best and then felt so stressed and frustrated that you are focusing it all on someone else.
What she said certainly didn't help a difficult situation and it was probably a lot more blunt than many people would have been.
But from what you have described, that your son was over tired and upset, almost broke a glass coaster, wanted to colour in a room filled with white upholstery, repeatedly jumped on chairs and making a beeline for them after you had moved him, looking in all the cupboards and being into everything etc, it sounds like it went far beyond her not moving a few ornaments and I'm not surprised she spoke up even though you were trying to deal with the situation.
And you seem to be blaming her for not moving her belongs and focusing on that. You've said that you were embarrassed and shocked by her comment and I think that's a fair reaction, but you've also said that the only thing that irritated you was that she didn't move the ornaments, as you were brought up to do, said to not move them is "stupid and dangerous", asked if you are alone in being brought up to move eye level things away from toddlers etc, said you are annoyed at people who make no effort to toddler-proof (I think that's what you said anyway, that post at 09:30:55 wasn't entirely clear).
But as you have seen, not everyone will do that and they shouldn't have to, so the safest way to ensure this isn't a problem in the future is to either be more confident about refusing an invite if you feel your son will be overtired and hyper and to accept that some people will expect you to manage your son in their home as it is rather than change it themselves to suit him, regardless of what you would do in your home if they brought a young child to visit you.
And you are being a bit rude to people here, as people have been quite gentle on you really, especially since nobody pointed out that it has gone from being a few trinkets to a collection of sharp glass things etc. That sort of thing is normally jumped all over in AIBU.
Asking if someone has issues with reading, saying several people are twisting your words, calling someone else a liar and insanely aggressive and a disgusting excuse for a human being is wrong. Nobody had said anything like that to you and nobody personally attacked you until after you had been rude to them first, when they responded in a similar manner to the one they were being spoken to in.
I'm not trying to attack you either but I do think you might feel better if you take a step back and calm down yourself and have a think about why you are really feeling so stressed and angry about it all.