I don't know if you still need it, but my friend did this dress and used Simplicity 9891 for the dress. Just modify the sleeves to not hang down as far, and don't add the neck cowl-thing. It turned out really, really well, and besides those couple things, the dress is pretty much perfect.
'Idiot's Lantern' Rose Tyler (Doctor Who)
Astrid (How to Train Your Dragon)
Tinkerbell (Peter Pan)
Reviving This Year:
Annabeth Chase (Percy Jackson)
Katniss Everdeen (Hunger Games)