I second Eden's comment about the promoters!
The other challenge is to teach new women skills, and to maintain contact with them through the season to ensure they have picked those up, and are progressing. Kind of like a mentorship program. One of the things our club realized last year is that learning from an experienced FEMALE racer/rider builds more confidence and self-esteem.
The skills are importatnt though - those squirrelly women who come out to race because their BF or DH is racing are dangerous!
SheFly