Riiiiiight.

You are training to be a CFI, now start acting like a CFI. Just because something is legal, does not mean its safe. You are now a risk manager. There is no way that the risk here justifies the reward. We hear maybe once a year about some private pilot taking his family up and killing them all. This is kinda like that situation. Know your skills and don't do anything that would make your or your friend's mom go through their worst nightmare.