The only "concern" I have is that she needs to develop her lats. Eating massive calories will take care of the bottom half, and the costume will pad her up front. Her arms look great. She is already going from waif to healthy. Great lats will make her figure go from waif to WOW!
Note: I don't want wonder thongs, those are just stupid. Chiang or slightly longer would look very cute. Even the original shorts that were almost biker shorts length would work if the color was dark instead of light blue, and not all star spangled...a couple to 3 stars on the side would look best.