hello! Luckily, I actually own this pattern, because it is super cute and will make a great foundation for a Peggy Carter costume, but I have yet to actually make this myself. But I can at least look at the directions and we can see if we can figure this out together. 🙂 So for step 13, yes, you should turn the sleeve right side out after completing step 12. Then at the bottom of the sleeve, turn up 1 1/2″, which is the hem allowance that’s stated on the pattern. You can just turn up the whole bottom of the sleeve 1 1/2″ just to make it easier. (If it were me, I’d also give it a quick press. It doesn’t have to be a crisped, iron edge but it might make it a little easier to see where your hemline is when you get to step 14.) But you’re only going to stitch the 1/4 seam on the part of the hem that lines up with the raw edge of the side seam. Once this is stitched, you should be able to flip this 1 1/2″ to the inside of the sleeve and now, from the outside, the bottom of your sleeve should look finished….at least at the hemline with another quick press. I know that pattern directions can feel somewhat overwhelming especially if your a novice but just keep doing what your doing and take it one step at a time 🙂