Although fans and critics have panned Kristin Stewart's as-usual wooden performance, at least Snow White and the Hunstman had beautiful cinematography and fabulous costumes. Thus possibly prompting many people to wear Snow White and the Huntsman costumes this year.
There are a couple different variations on Ravenna costumes for adult women, mainly based around the differences in gown style and headwear. You would probably want a blonde wig in either case if you were trying to accurately mimic the movie character. Also sold on Amazon.
Check out the cool fingertips accessory you can get to go with your Ravenna costume!