Help With My Dress

Hi everyone ok see im hoping you guys could help me out on ways to decorate my nieces quinceanera dress because we bought it but it came out so simple its just basically a white dress with a pink ribbon around the waist and thats it so in a way it turned out to be a little girls dress and i can tell she doesnt like it so we would like to decorate it ourselves but we arent even sure how so if you could please please tell any suggestions will do.....thanks a bunch:)