What does Ismene mean when she says, "We are only women, we can't fight with men"?

When Ismene speaks of women's weaknesses and how this makes them incapable of fighting with men, she communicates a traditional view of women in society.

Antigone has asked Ismene to help her break the law in giving a proper burial for their brother.  Ismene knows that doing so means breaking the law that Creon has established.  When she tells Antigone that "We are only women, we can't fight with men," it conveys Ismene's view of women...

When Ismene speaks of women's weaknesses and how this makes them incapable of fighting with men, she communicates a traditional view of women in society.

Antigone has asked Ismene to help her break the law in giving a proper burial for their brother.  Ismene knows that doing so means breaking the law that Creon has established.  When she tells Antigone that "We are only women, we can't fight with men," it conveys Ismene's view of women in society. Ismene believes that women are not in the position to question the laws that men have made.  She does not think that women have the strength to challenge the patriarchal authoritarian structure.  Ismene believes that it is not their place as sisters to "go against the king's decree and strength outside the law." She believes that the lack of power women hold in society would make it pointless for them to challenge this structure.  Ismene hopes to dissuade Antigone from proceeding with her plans. She seeks to do so by reminding Antigone of the place that women occupy in Greek society.  

In suggesting that they are "only women," Ismene embraces a traditional view of women in society.  This is in stark contrast to Antigone, who has no problem in breaking what she sees as an unjust law.  Ismene's appeal to her sister is based on the idea that women are better off not questioning a system that does not treat them well.