In the plays Antigone and Hamlet, Antigone, Gertrude, and Ophelia are all tragic victims, though only Antigone, I would say, is a tragic hero.
Antigone is a tragic hero because she incites the action of the play, makes a tragic mistake, and suffers dearly for it. Her rebellion against Creon's unjust civil law causes her to suffer and die. And, let's face it, she makes the tragic mistake of being stubborn even after she proves her point. She goes to her death full of tragic hubris (pride), a romantic zealot with a death wish.
Gertrude and Ophelia get caught in the cross-fire between the tragic heroes Hamlet and Claudius, but their roles are not enough to be classified as tragic heroines along side Antigone. Instead, I would classify them as supplients who provide vision of unmitigated suffering and helplessness. This is an archetypal term used by critic Northrop Frye, who kind of wrote the book on classifying characters.
- All three die, obviously, but their deaths can all be blamed on the state (unjust laws, kings).
- All three are blind: Antigone to her pride; Gertrude to her son and husband and Ophelia to her father.
- Antigone and Ophelia suicide, but Gertrude's death is murder
- Antigone and Ophelia are victims of incest, but not Gertrude (who commits it herself). Antigone's family is cursed by incest: she is the daughter/sister of her brother/father Oedipus. Ophelia is caught up in Hamlet's revenge against incest and adultery, not to mention her brother's and father's incestuous-like jealousy of her and Hamlet.