Interesting how people think sitting around fantasizing about screaming at the girl and beating her up is somehow far better than her clumsy attempt at charity fundraising. If any of you honestly think that's anything like an appropriate and justified response, you need some serious help.
But yes, I also would not be thrilled to get that message. I can conceive an appropriate message on the subject, possibly, depending on the rules and culture of the company, but telling co-workers (as opposed to friends or family) how much you're giving is not cool, and it needs to sound more like a request. Unless there's something we're not being told, being in the Peace Corps didn't give her any authority over others in her current job, and she needs to take a less pushy approach.