The Greeks believed in fate and divine force.Ismene wants to obey Creon's orders and tries to talk Antigone out of it.Antigone wants to give her brother a proper burial, she believes family is greater than law.
Ismene is Antigone Lite. She first puts in an appearance along with her sister at the end of Oedipus the King, and both girls seem to be symbolic of the legacy of shame left by Oedipus's mistakes. In Oedipus at Colonus, Ismene shows great loyalty to her father when she alerts him to the situation with Creon. She shows devotion once more when she returns with Antigone to Thebes. In Antigone, however, we see that Ismene's loyalty only extends so far. Though she agrees morally with Antigone’s decision to bury Polyneices, she is afraid to risk her own life.
Like her sister, Ismene seems to value family ties and the laws of the gods over the laws of man. However, she's just not gutsy enough to stand up for her beliefs. The courage to stand beside her sister does eventually come to Ismene. When Creon arrests both daughters of Oedipus, Ismene asks that she be executed alongside Antigone. Antigone, however, scorns Ismene's belated attempt at righteousness.At the urging of the Chorus, Creon eventually relents on executing Ismene. The girl ends the play with her life intact, but her self-worth in shreds.