With all due respect to aterpster - and with the disclaimer that the NTSB personnel that I've dealt with have been male, my experience is just the opposite - there are far more dedicated female participants in the aerospace and aeronautics field than ever before.
When was in college (Aero Engineering), I could count the total number of females in our class on one finger (there were roughly 30 males). Today, while it's not quite 50-50 with males still in the majority, it's close.
I've seen a similar response at Boeing - 35 years ago, the percentage of female engineers was single digits (granted, most secretaries - sorry, "Office Assistants", and tech aids were female). Today, it's more like 1/3rd of the engineers female, in some areas over half. Further, most are very good engineers and show a passion for airplanes. It's also been my experience that there is a small percentage of 'dud' engineers among the females.
As noted, I've not dealt with any female investigators in the NTSB, but several of my counterparts in the FAA are female, and they are every bit as good as their male counterparts - in some cases even better.