Because of shaking some people awake. And because of the content of the message. To me personally it could have been anyone delivering the message, but I am glad, that she reached lots of people. Starting this at the age of 12 (iirc) is remarkable, even if it does not change the message. Although one could argue, that it does add a kind of meta message: "Look here, I am a child! I will have to bear the consequences of your (in)actions!"