It's impressive that she went through all of that extra effort to solicit submissions from a particular group and then didn't give any special preference to that group when accepting submissions.
Gender was not considered when deciding on an applicant, but they made quite an effort to get more qualified women to apply, and to get those who did and were offered admission to choose Caltech.
This isn't the fastest way to balance the population (when I was there, 10 years later, they were only up to 15-20% women, and are up to around 40% now), but it allowed them to keep their high standards.