No girls here but there were several all girls teams at the JFLL/FLL competition as well as mixed-gender teams.
the think about FLL is that there can be something for everyone. Some teams are quite large w/ 8-10kids. Some kids don't like building but like programming. Some will like building but not programming. SOme kids do most of the research. The discussion w/ the judges can be an important part of the competition especially if you're lacking points on the robot performance end - from what I've gathered.
Also, for those interested, 4H now has LEGO MINDSTORMS clubs as well as K'nex clubs. they are solely centered on those two platforms (you don't have to have cows lol). So even if your local 4H doesn't already have one, you can contact them about starting one. If they don't know what to do, I can put them in touch w/ the head of our 4H here. the LEGO Mindstorms ran an ad and got twice as many kids as they expected. they were scrambling to try to get more robot kits.
My friend runs a robotics club. I think she strives for 1 kit per 3 kids at the most.
