For the most part, I think everything looks really good! I actually really like your shoes - they were one of the first things I noticed. Can tell much about the headphones; they look good, but if you want to remake them, go for it. If the shorts are too long, it would be much easier to just hem rather than remake them, especially since there isn't any trim to pick off. I think Rin has cuffed shorts too, so that might make it even easier.
I'm not super familiar with the character, but I think the lace you're referring to is the yellow trim on the hem/armholes of the shirt? I think using a larger sized ric-rac would be appropriate for this, as you would avoid the hassle and cost of finding and dyeing cotton lace to match.
The hair pins seem to be sliding around a fair bit - might want to put a few stitches in to secure them directly to the wig. The leg warmers are missing a bit of detail, though it might just not be visible in these photos. You could go all out and wire some LED's into them, but I honestly think a couple dots of yellow fabric paint would do the trick.
I think the biggest thing is your makeup. Don't be afraid to pile on the eyeliner and always fill in your eyebrows. The close up picture looks nice (possibly even different from some of the pictures?), but it will still be washed out when seen from afar. The makeup board has tons of tricks. Get a good black eyeliner and practice shaping your eyes with it. As for brows, if you don't fill them in, they'll disappear in photos. You don't have to make them darker (unless the character calls for it), just get a blonde brow pencil and fill in everywhere your brow grows. I might be going crazy, but I think you have this done for about half the photos.
All in all, well done. Any ideas on what you'd like to tackle on your fist from-scratch cosplay yet?