Wolfstar, this is close to what I've been saying and I agree with most of it. I'm not as convinced about the time intervals between injuries but that is not THAT crucial at this point. Yes, the head trauma was fatal, no question about it. The entire right hemisphere of the brain itself was bruised 5 mm deep. This is massive. It is rage.
The ligature part is harder to interpret IF it came after the head wound -- intentionally squeezed with all one's might for deception's sake or done that way out of pure rage? I don't know and I don't think we have any way of answering that w/o more info. I can't second-guess how twisted a family member might be as to what lengths they will go to deceive.
We'd need a medical doctor to help by providing a professional estimate of how long the child might have survived with that head wound. My guess is only a few minutes, at best, because of the massive bleeding in her head. Her blood pressure would have dropped pretty quickly, leading to heart stoppage. In essence, she would have bled to death internally.
On the other hand, near as I can tell, all of the trauma was under the skin. I don't recall ever seeing anything that indicates there was external bleeding on her head. I don't know if that would have any bearing on the length of time her heart was able to keep pumping after the head trauma.
But I'm glad you agree about the rage killing aspect. I think it's obvious.
BTW, the ligature had to come after the head wound. The strangulation definitely would have stopped her breathing and her heart. There was massive internal bleeding from the head wound, which means her heart was still pumping for at least a short time after she suffered it. Again, a medical professional might be able to help us further understand this point, but I believe if she was hit after being strangled, there would not have been that massive internal bleeding.