One yard split in half yields six stripes, which are certainly enough for a 2T dress (my project); if you made shallower pleats, of course, you'd have a bigger waistline. To keep the dark-green-only-inside-the-pleats movie look, or for a much taller kid, you'd need more. Comes in separate one-yard cuts, not continuous.
The pattern that must show on top (the two narrow stripes plus the stripe with the design on it), according to the guide on the side, looks to be 7.5 inches across to me. So all the green would be underneath in the box pleats. It's so big a pattern, that on a small kid you would have only two in front and back. Even on a grown person it would be not much more and would look skimpy. I wish they has a half size with the box pleat, the way they do with the kind you would gather. As it is, I am making this for a T4 size and so I will go with the smaller pattern and just gather it.
Do you have a solid color version of the bodice fabric that would match this fabric like you do for the pinker colorway? (for the sleeves and the fabric under the bodice) That would be extremely helpful!!