IMHO she does things the hard way. I make dust ruffles by fitting a fitted sheet to the box springs and then measuring and marking on the sheet two inches from the edge...this becomes your guide for sewing. Measure from the top of the box spring to the floor and add your hem measurement. Then I measure the length of fabric needed for each section and either add 1/2 that amount or double that amount (depending on fullness)....cut the fabric needed and gather. Hem the bed skirt on bottom and end pieces. Place this fabric right sides together (with the bed skirt fabric toward the middle of the bed)and sew on the line marked on the fitted shit. When you place the fitted sheet back on the box springs your bed skirt is complete and won't move around.