Most Helpful Guy
i like the look of the lighter color dress. it look more attractive
Most Helpful Girl
Depends on whether it's going to be inside or outside, first of all. The shorter dress if it's outdoors. and personally I'd pick the short dress anyway because it's a bright happy colour, not too clingy, classy, and not overdoing it. The blue dress makes it seem like you want the attention more on you and not your sister.