Personally, I was lukewarm on the still pictures and found them inconclusive; but young miss DePaul did a great job with the video. The zoom onto the images clearly boosts everything you said about the pictures based upon my knowledge of children, to which I inadvertently paid a lot of attention to, due to my only sibling being 10 years younger than I, and being around lots of her peers when I was in high school - the irregular arrangement of the teeth as they come in, the facial features, even the luminosity of Natalia's prepubescent skin - really everyone "on the fence" should watch this video before they make any decisions; and I'm appalled at the reaction of the idiotic YouTubers characterized in the screenshots. The comments are so much worse than anything you all alluded to in generalities...
The Barnetts are diabolical, there's no other word for it. They so plainly created a farcical narrative THEY believed in, and tried to make the reality fit the narrative; to the point where they even have their bio kids (IMO) brainwashed into believing it.
This is so clearly an exemplar of the phenomenon my own therapist calls "Othering" on the part of the Barnetts, that I feel it should be the visual illustration of this condition. This entire narrative consists of **their** believing that N is an abnormal freak; and then digging for so called "experts" to dragoon into their lane. To be frank, I trust a physical therapist, expert in musculoskeletal conditions (and who would at least have studied in-depth once getting Natalia as a client), about 1000% times more than I trust a suburban general practitioner family doctor (no offense intended to suburban GPs).
Living in NYC, I actually see quite a few people of diminished physical stature moving out and about on the streets (the apartment complex where I live, even has a pair of female adult twins); and disregarding the twins, I doubt I've seen more than a dozen individuals with dwarfism walking down the street in my 20 years. I don't think it is a common type of thing you see in anecdata; and I don't think if you weren't an "expert" in it, that you would know anything about it, to be frank - simply because you wouldn't need to.