I wouldn't go that far. Little girls can be very manipulative and yet perfectly normal. Psycopathy requires things beyond playing games with adults. This particular girl just doesn't respond well to artificially-imposed authority figures. Her form of lashing out is simply more aggressive than standard coping mechanisms which, with girls, often internalizes things (shyness, self-destruction etc). Frankly, I give her points for demonstrating the absurdity of the assignment while at the same time operating within the rule. I fault the teachers for not anticipating this.
(In my day, the popular option for such assignments was "starship captain".)