I am NOT in any way defending this woman or her actions. I personally find her behavior abhorrent. However, it's possible she only deleted her accounts just to keep people like us from speculating on them, not with the idea that LE can't recover everything. I could see myself doing the same thing if I were ever involved in a high profile case, even if I were innocent. Which I would be LOL. Not so sure about her, though. JMO.
I would delete everything just to keep everyone away.