Looks like a sweet kid but I cringe when I hear her. She is trashing her voice by singing music not meant for children to sing.
Can you explain what you mean to a non-singer like me?
Are you saying in order to produce the full octave range with the power that she does, one would damage or quickly wear out the voice, the lungs, and the diaphragm?
I recall the late Florence Henderson was rumored to have had ribs removed as a young girl because this would help her singing. I don’t know if that was just an urban myth or what.
You shouldn’t cringe when you hear her sing. She is not trashing her voice but is being trained professionally and being brought along slowly so as not to ruin her voice.