It needs to be okay for women to fail. We need flawed women whose mistakes represent just that -- their own mistakes. Not reflections upon our entire gender, not held up as reasons for why women aren't meant to be in tech. We need to accept women in this field who want to be here just because it's a great place to be.
I don't believe that girls are turned off by STEM because it's hard or simply because girls think they're bad at math. Girls aren't wimps or wilting flowers; they don't shrink from challenges just because something isn't a strength. We, as a culture, just aren't doing a very good job of selling tech to girls.
Now we've got the Internet, held together with code, infrastructure where people can build tools which unite regular people for collective influence. The Net tends to level the playing field, and that tendency only increases over time. That is, the Internet is dramatically lowering the cost of influence and power.