|Before starting you need to cut a piece of buttonhole elastic that goes around the child's waist minus 2 inches. Example: My little sister's waist is 20 1/2 inches. So, I would cut a piece of buttonhole elastic 18 1/2 inches.
After doing this, follow these steps: Step 1 & 2 (the buttonholes are sewn 3 to 4 inches away from side seam), Step 3 & 4, Step 5 & 6, and Step 7 & 8.
This is a nice way of making the waist size adjustable. As the child grows you can make the waist bigger as needed.