The NSF has a GK-12 program for general Science and Math outreach. The program sends Graduate students into classrooms in order to inspire students and teachers. There are requirements for female participation and the program I was involved with did a good job.
My bet would be that if you could figure out a way to better target girls there would be funding aplenty. I taught math at both the high school and college level. By that time women/girls have been thoroughly inculcated to the belief that they suck at math. This is infuriating.