That's not how storybooks or children's tales are supposed to work though... characters don't make dumb decision just to make dumb decisions. There was no self-motivation for her to make that decision, so what lesson can be taught? Kid's can't learn lessons from this cuz every kid watching already knew how dumb she was being. If they gave her some motivation to eat - maybe she was starving or there was a particular food there that was her favorite and exotic - then maybe you could get a lesson across, but the only motivation in this scene is to get a chase scene.
Even in children's books, kid's aren't supposed to make dumb decisions just because they are dumb, there is supposed to be an underlying reason that they semi-rationally choose to make that dumb decision.
Swatting away the fairies makes it even stupider. It would be a better lesson if she forgot the instructions and ate it impulsively - the lesson would be, "pay attention to directions and be wary," but she defies the fairies which NO KID watching this would have done because even if they had foolishly/impulsively forgot their instructions, they would have clearly been reminded