The first time is HERE
Using skirt piece of a baby dress, some elastic or knit, your little girl will have
a new skirt.
For a knit waistband you can reuse an old shirt or knit pants (as seen at here) if no knit/jersey on hand. I love knit waistband because it´s soft for kid' belly.
Cut your knit piece as showed above, you decide how high it should be, then sew into a tube using light zig-zag or stretch stich.
Fold the waistband in half lengthwise with the wrong sides together
GATHER the skirt piece automatically: highest tension, longest stich, sew about 1/4" from top edge.
Insert the gathered skirt piece with right side out into the waistband tube as showed below and pin evenly in place.
Don't stretch the waistband as you're pinning.
Serge or zig-zag those layers together (3 layers in all), using a 1/2 inch seam allowance
You have that
Pull the gather thread out if needed.
I tied a bow from the old strap of the baby dress and saw it on the waistband because my daughter wished that.