While big cos. might have programs to address women's issues, that's not stopping women from forming more effective support groups and organizations.
Let's look at an effective lobbying group, the NRA, how are they so effective? They are tenacious and they organize nd support each other --so while they do appeal to greater society and parties, that by itself isn't what's driven their success. It's the forming of community and having one focused issue.
Also as with other groups, tap names in other industries, entertainment, sports, politics, etc. those who are interested in advancing your issues. Tap companies with black founders or ones directly serving the community.