A couple more things - in posting your stats, realize that a small minority of people are getting into Stanford based on an academic hook. As this post explains pretty well, those people have nearly perfect stats plus some major regional, national or international academic achievement: http://talk.collegeconfidential.com/discussion/comment/17848258/#Comment_17848258
That said, you still need strong academics as a threshhold to get into Stanford, but that’s different from saying if you have strong academics you will get in. Fortunately, you have strong academics so you are in the running.
From that point, the question is, how do you fit into the class Stanford wants to build? My favorite extracurricular on your list is your being a hostess. It is a real job in which you are given the responsibility to positively represent a business to the public in repeated social interactions. It rounds you out, especially when combined with the fact that you seem equally comfortable interacting with disabled students. Further, you are strong in AP Bio, Physics, and Chemistry; volunteer at a hospital; shadowed a nutritionist; are taking anatomy. Pre-med, right? If so, you seem to have a great combination of smarts, empathy, and strong interpersonal skills. Sounds like a wonderful doctor to me. And I don’t know what your international visits involved, but if your interests include worldwide health policies then even better.
In any event, whether your journey begins at Stanford or somewhere else, I predict you will have an opportunity to build a wonderful career for yourself.