Mrs. Warren's Profession comments extensively on the position of women in society. Shaw uses a motif in the play that continually compares the limitations placed on women to a kind of slavery.
This motif is a common one, featuring heavily in early/first-wave feminist rhetoric, which positioned women as the victims of patriarchal oppression. Many important works in early feminist literature featured such rhetoric (i.e. Wollstonecraft's Vindication of the Rights of Women). While this point of view was an important one in the history of advancing western women's rights, it should be noted that such first-wave feminist rhetoric aggressively centered white, middle- and upper-class women. Black women, indigenous women, and poor women, among others, often had their concerns sidelined by such rhetoric, even if they were themselves the victims of imperialism or enslavement.
In Mrs. Warren's Profession, Mrs. Warren positions herself as an opponent to systems of patriarchal enslavement at the end of Act 2:
VIVIE. [more and more deeply moved] Mother: suppose we were both as poor as you were in
those wretched old days, are you quite sure that you wouldnt advise me to try the Waterloo bar,
or marry a laborer, or even go into the factory?
MRS WARREN. [indignantly] Of course not. What sort of mother do you take me for! How could
you keep your self-respect in such starvation and slavery? And whats a woman worth?
It should be noted that in this passage Mrs. Warren proposes her own sex work as a freedom-granting alternative to the "slavery" women must endure under patriarchy and capitalism.