Hence my whining. I hope I'm very wrong.
Basically, it comes down to helping someone who is part of a cultural minority maintain their identity (in this case, women's culture) while they are dipping a toe into the waters of the different culture. That's why groups like PyLadies are useful and important.
The research supporting creating these groups is why I believe they ultimately will work to increase the number of women involved in open source, and the tech world in general.
Now we just have to collect data about what we're doing that works and what doesn't, and try to spread the knowledge as fast and as far as we can.