Your child got an A on her quiz.  Should you praise her for being "so smart"?  Maybe not.
      Research shows that kids do better when they're applauded for effort over intelligence.  That's because intelligence can feel like something they're "born with," whereas effort is something they can control-and improve.
      So congratulate your child for her hard work: "All your studying really paid off!" 
      It may inspire her to buckle down next time, too!