Ribbed knit--such a versatile fabric. The difference in using knit over cotton for a skirt is how it lays on you. The form-fitting aspect of it means a bit more tailoring in the process of making a skirt, but no fraying or hemming.
Here's my take on a sporty knit skirt.
ribbed knit- 3 feet by 1.5 feet, contrasting knit- 3.5 feet by 8 inches (for a girl's size 5 with lots of room to make smaller)
sewing machine with stretch stitch (usually putting length down to a 1)
You will need your little model quite a bit for this skirt. Wrap the larger fabric piece around her, not snugly, to get an idea about where her hips round out and where the skirt should flow straight down. Mark it on the skirt with pins her little figure from waist to hips to top of thighs.
With your length on 1, with right sides together, stitch down one side of the skirt, following the pins to keep her figure.
Beginning to sew with knits means some trial and error as you get used to stitching on stretch fabric and as you discover how it lays against skin. Sew together the other side the same way. Trim seam allowance.
Most important step: try it on your model! I adjusted and brought in that curved seam around her hips a couple times to get it where I wanted it. That's why I like to give myself extra fabric to work with so I can get the skirt to fit perfectly.
Once the skirt fits the model's body comfortably, grab your waistband. Fold it in half, lengthwise, right sides facing together. Sew a 1/2 inch seam, this time helping to pull the knit through the machine since you're sewing through the ribs horizantily.
Turn it inside out.
Try the waistband around your model, giving yourself about an inch of overlap. Sew the waistband ends together 1/2 inch and trim.
Place the waistband around the waist of the skirt, right sides together, and pin.
Sew 1 inch all of the way around the waist.
Try the skirt on your model to determine the length.
Cut carefully because this will be your hem. (Hemming knit is messy. This is the best part of sewing with knit.)
Now the model can try it on complete!
This is how she's starting to feel about modeling for skirt week. At least she gets a skirt out of it. We won't tell her sisters. (Or that she's wearing her sister's shirt.)