Maybe she made two, one for her, and one for Crump. Even if she only made one, writing things down can help with the memory.
-- What I do see is Witness 8 scribbling these words on paper to have in front of her or to review before her April 2012 interview or even her March 2013 deposition ... --
It doesn't mirror the April 2012 version very well.
It could be deliberately pre-dated, as you suggest. All sorts of possibilities. But even taken at face value, I don't see it helping the prosecution.
I don't either. So then why release it. No one knew Sybrina had it. It's not addressed to her. This could have easily been dropped in the round file or filed away and it would have never been missed.
So why dredge it up and dredge it up now at a time when Witness 8 is about to be unmasked???