Unfollow or unfriend on social media - do not waste your time. 
If she comments on what you wear to your face - tell her that you do not appreciate the comment and it should not be repeated. Period.
Now: is her belt or shoes made out of cardboard? Are her clothes made in a sustainable manner with workers paid a fair price? Is she a vegan? The answer is probably no, so the hypocritical girl can shove it.