She’s in a lose-lose situation. But she probably fears the pro-Trayvon forces more than the common-sense folk who believer we are still a nation of laws and not of men. She probably is in fear for her life if she doesn’t charge him.
I read her for the opposite. She may delay an announcement based on the governor and police suggestion about the strength of the mob, but she's been prosecuting criminals for years, and death threats are part of her daily life already.