Enter Mom. Her daughter, Diva, did absolutely NOTHING in my class except stir up drama, be extremely rude and obnoxious, and generally anything but do her work.
Now, student grades are easily accessible at all times through an online parent portal, so I have always been of the opinion that parents should never be surprised by grades at the end of the quarter.
However, any principal I've worked with also knows this about the parents, so they put on a show to calm the animals down but trust you to do something to try shutting them up next time.