This kit includes 1 yard of Birches cotton jersey, 2.5 yards of Storm Fancy Foldover elastic, 4 yards of Storm Foldover elastic, a Bralette Finishing kit with 5/8" lower and Foldover, 3 hook and eye and 1/2" strap in Storm.
This should give you enough for 2-3 panties and a bralette, which is relatively possible with a size medium, depending on how much coverage you want with your undies.