My compliments to you! Though this is an iconic character of Science Fiction, often portrayed by some of the most respected illustrators of the genre, I don't think I've ever seen anyone attempt an accurate costume before. Its truly ironic, really, because the "Princess Leia slave girl" arch-type that is done to death, is so similar to some artist's interpretations of Dejah Thoris.
The truth is, it takes a considerable degree of courage and confidence in one's appearance to wear a Princess of Mars costume that's in any way accurate to the source material...well done. (It doesn't hurt that you actually have the right build and hair color, either.) Good job!