I hesitate before posting this, but it's something I can't really shake from my mind and your post reminded me of it again.Maybe the roof camera that was recovered showed she was not alive when she was abducted? It didn't sound like second note confirmed she was dead--unless there was specific info in that communication hat only the family could interpret this way. Very sad. I really can't imagine the family's pain.
The first day the photos were shown to the public I went to the Daily Mail online website and scrolled through some of the comments, taking most with a huge grain of salt; however, one of the comments stood out. It was about the blood by the front door. Someone (who may have not know what the heck they were talking about) said with some degree of confidence (again, stranger on the internet so consider the source): the blood appears to have been blood that was aspirated.
My apologies to any and all if this is inappropriate speculation.