Consider the character of Jocasta. Is she a "flat" character—a generalized queen figure—or an individual with distinctive traits or personality? Point to speeches or details in the play to back up your opinion.

Jocasta is more than a generalized queen figure. While she does have noble bearing, she is made distinct by her love of her family. In her first appearance, she calms a dispute between Oedipus and her brother Creon, reminding Oedipus of Creon's loyalty to them in the past.
Her most distinctive trait is her disbelief in the power of prophecy or fate. When Oedipus shares his concerns about the prophecy claiming he will kill his father and marry his mother, she tells him not to worry, prefacing her story with, "Listen and I'll convince thee that no man / Hath scot or lot in the prophetic art." She tells him the story of how her former husband, Laius, sought to defeat a prophecy that his own son would kill him by abandoning their then–three-day-old child on the mountainside. Later, she even laughs off the idea of the prophecy in full, telling Oedipus:

This wedlock with thy mother fear not thou. How oft it chances that in dreams a man Has wed his mother! He who least regards Such brainsick phantasies lives most at ease.

Unfortunately, Jocasta's confidence (some might even say arrogance) is shattered. Ironically, she learns Oedipus's true identity before he does. When he becomes more fervent to learn the truth of his origins, she begs him not to or else he will be "miserable" for the rest of his days.
Unable to handle the fact that she slept with and conceived children with her own child, Jocasta hangs herself—not to save the state from the curse or atone for the incest, but to escape her own pain. And this detail further disproves the idea that Jocasta is merely a queen figure. She is very human, experiencing the same shame and horror any person would in such a situation.
http://classics.mit.edu/Sophocles/oedipus.html