When I am wrong, I will admit that I am wrong. In this case, I still can't BELIEVE I was wrong...but I was. My daughter can apparently sell ice to an Inuit...because despite my dire predictions I made here, she did, indeed receive permission to include a gun-powder-using projectile device in her physics project.
Here are some views of said project:
You do not see the cannon in any of these pictures...because I absolutely forbade its use in my livingroom.
Here's the contraption in action:
And nobody shot their eye out.