We've all heard of the Bechdel test. I know it's not a cure-all to sexism and hidden patriarchy, but it is a good question to ask as a writer.
For those who don't know, the original "Bechdel test" posited that 99% of movies don't have two female characters talking to each other about something other than a male. Basically that women in fiction usually exists just to further the plot of male characters.
My novel is first person PoV of a middle school boy and he's part of a trio with two other teenage girls (these are the main 3 characters). But because he is the only PoV, it can never pass "the Bechdel test." Otherwise, I think I've made the other two main characters fairly fleshed out characters.
Yeah, my recollection is that it came from the fact that a lot of the time, even when a scene had nothing but women, the overwhelming majority of those scenes were just an excuse for the women to talk about one or more of the male characters. The Bechdel test is about asking the question "are these female characters actually real characters, or are they just props?"