Thanks everyone.
It's so hard because I want her to always be able to think for herself, and not define herself through other people's opinions of her achievements (or lack thereof). On the other hand, she needs to be able to navigate the societal/scholastic landscape. Expectations (grades or otherwise) exist, whether we like it or not.
MON - I tried asking her about the required elements for the project (like the bibliography), ie "have you included everything you're supposed to?" and she got annoyed and shut me out.
I have a friend with a HG son the same age, and if his work is not up to par, she puts her foot down and makes him redo it "You're capable of better, and you know it." That just wouldn't fly with my DD... oh my goodness... look out. (Is that nature or nurture? How much influence do I have over her temperament? Have I handled her in a less than optimal way?) I second guess myself constantly.