Alpha Bitch: Once Marcia gains her self-assurance that she indeed has the ability to play a major role in a Shakespearean play, her ego begins to grow ... big time! So much that her siblings are annoyed by her just being in the room because she's going to talk about how great she is. She insults her castmate, an awkward kid whose voice is still cracking (she calls it "squeaking," which upsets "Romeo") ... and she becomes rude to her teachers and others at school.
Arson, Murder, and Jaywalking: At the end of the episode, when the family returns home from the play, Alice comments that, as sad as it was when Romeo died, followed by when Juliet died, the saddest part of all was "when Jan said 'Who goes there?' before Peter said 'hark'".
School Play: Shakespeare's Romeo And Juliet, with Marcia cast (initially) as Juliet. Marcia at one point interprets her role in this as her next big break for Hollywood stardom, instead of considering this is just a junior high play to be enjoyed for the moment and to learn from.
Small Name, Big Ego: Marcia's ego swelling to mammoth proportions, to the point that she thinks she's the greatest diva/actress in the whole wide world and she doesn't have to cooperate with anybody.