I serve on the CS advisory board at another college that competes head to head with Harvey Mudd for students. Generally, when one of these schools celebrates having more women or a higher ratio than the others, it means they've managed to recruit more of a static pool rather than growing the pool.

The college that I advise at took another approach to grow the pool while also recruiting better from the pool. They encourage profs to work with Girl Scout troops on science projects, to get students to tutor junior high and high school kids in general, and build relationships long before the normal "I have to think about college" thoughts begin.