How might it have changed positions?
Well as we know she could have been conscious between shots and she could have moved herself for the second shot or when she possibly put her hand up between shots ?
I don't think it's was moved after the second shot because of the pattern of blood .
Not saying it is relevant although it could back up her being conscious in between shots .
As I have never seen a diagram of how Jeremy is supposed to have shot her without her fighting back I can't comment on how he would have done it .