How is feminism projected in the play?
In so far that Virginia Woolf's writings on feminism and pacifism are helpful in understand other texts, what she says about Antigone greatly pertains to your question. Woolf studied Greek under her tutor Jane Case, and the figure of Antigone fascinated her. Woolf judged Antigone “the perfect type of heroic woman: unflinching & uncompromising” even though she was also dismayed by Antigone’s dismissive tone to her sister: “her bitterness to Ismene is always unpleasant.” In Three Guineas, in which she most clearly articulates her position against war, Woolf specifically invokes Antigone by arguing that “daughters of educated men” should, like Antigone, act as outsiders to patriarchal society, forming a “society of outsiders” that will refuse to participate in war, which Woolf understands as a result of the tyranny of men, a function of the patriarchal culture she saw in her own day, during WWII when she wrote Three Guineas, as well as in Sophocles’ day, when he wrote Antigone. Using a search engine with "Virginia Woolf" and "Antigone" as key words will give you a good deal of information on this topic.
Essentially, feminism is projected by the mere fact that Antigone stands up to Creon. The society was paternalistic, to say the least. Women had few rights: whom the would marry, denial of property, no money of their own. Moreover, to go against the orders of a king was a death sentence for man or woman.
Robert Fagles argues that Antigone is her own person to the very end. "She will not yield a point or given an inch," Fagles says. "She will not yield a point of give an inch: "she hasn't learned," says the chorus, "to bend before adversity" and she never does. Those who oppose her will are met with contempt and defiance."
Antigone's "feminism" stands in stark contrast to that of her sister, Ismene, and Euricyde, the queen, who constantly bend their wills to that of Creon and men in general.