Teaching young kids how to act defensively is an excellent idea, and should be part of every schools' curriculum.
As far as we know, there were no defensive injuries on JBR, on her hands, etc. that would suggest she fought an intruder. The scream is about as much as we have right now, and her scream could have been in reaction to feeling the pain of either being sexually assaulted (enough to cause bleeding), or screaming in fear if she realized what was happening. Neighbor Melanie Stanton, when first mentioning the scream, is sure it was a child's scream. As a mother myself, I do know what she means; kids screams can be distinguished from adults pretty easily. However I don't rule out the possibility that the scream may have been PR's. A woman can have a higher pitched voice that can be mistaken for a child's, especially when the person that heard it was woken up from sleep by the scream.
THIS time, we get it RIGHT!
This post is my constitutionally-protected opinion. Please do not copy or take it anywhere else.