You know an 11 year old girl who can change a tire in 53 seconds? It’s the time and skill for her age that impresses folks.
Hey, considering how useless the average schmo on the street is supposed to have become, watching an 11 year old properly park, chock, jack, change the tire and check inflation and treadwear in a prompt and efficient manner would also be kind of neat.
She sure seems to have fun showing off this skill. Like others earlier in the thread, I can attest a large portion of my Basic Training platoon would only dream to be able to match her.
Sure, throw in video of her changing a motherboard and succesfully configuring and installing Windows on the first try, and we’ll be welcoming our new preteen overlady. But hey, that’s for next year 
the difference between an AR-15 and M-16 is what… a single part? For all practical purposes she is doing this to an M-16.
Try telling that to the ATF. “But the difference is only a single part!”
No, the difference is not a single part.
The differences include (off the top of my head):
Different bolt carriers
Different trigger groups
Different lower recievers- this may be as little as not having the appropriate holes drilled for a full auto trigger group or as much as no holes and a metal block where the full-auto bits would fit and/or different size hinge pins.
Converting a commercial semiauto AR-15 to safely fire full auto isn’t just a matter of dropping in a couple parts and blasting away. There are various half-assed ways to kludge things up so it’ll fire full auto only…and generally that also means that it won’t stop firing til its empty even if you release the trigger. Those methods also generally give you a high risk of the kludged up gun firing out of battery, which is really REALLY unpleasant for the shooter.