Don't get mad, just get even

at the end of the story, you can tell what bernice is planning to do because anyone in their right mind out do just the same.  when bernice cuts off marjorie's hair it is like a victory and your cheering for bernice as she makes each cut.  instead of bernice getting upset and just crying about her hair, she gets even.  any person in their right mind out have done the same thing.  is it one thing to be tricked by someone less close to you, but to be fooled by your own family calls for rash behavior.