This top is also from GAP about 6 yrs. ago. It’s the same color as the dress above so I cut up this shirt to use for the extra fabric.
I cut up the shirt into a long strip about 5″ wide and I also cut up the bottom of the dress because it hit me way below the knee which is a fashion no no for us shorties. And I used those extra fabrics for the waist-tie for the dress.
And instead of doing a gather like the one in Anthro, I twisted the fabric instead.
I didn’t take in the sides of the dress since the waist-tie did the work of making it smaller. It was a side-zipper anyhow so it would’ve been too much work to alter the sides.