I'm not as familiar with this problem as I'd like to be, so please take this with a grain of salt, but maybe you could invite female CS majors from nearby universities to come see your offices? Or better yet, to see what it's like to work with you for a day.
After all, one of the major issues seems to be that women don't see role models working in tech companies. If you have female students come and work with you, then they should be able to imagine themselves working at your company, or another small startup.
After all, one of the major issues seems to be that women don't see role models working in tech companies. If you have female students come and work with you, then they should be able to imagine themselves working at your company, or another small startup.