There's a difference between being courageous and a idiot. I think all of these traits are good, but to be a heroine you need to take risks and be prepared for the worst. I love Mulan for this reason, she has courage. My next choice would've been loyalty or compassion.

I guess intelligent too, but when I look at my most admired heroine (and I'm not thinking Disney, nor animated for that matter, although fictional, that's for sure) I realize courage is what I like the most in her.
I'd say loyalty for sidekicks and minor characters in general, it always moves me when a minor character shows that, or wisdom.