This is my first critique so bear with me. First I'll say that the lighting used here is impeccable. Nice soft lighting that really lights up not only the cosplayer's face but also the rest of her cosplay. The directional quality of the light does the cosplay justice in showing the details and form of the whole cosplay. There's also a slight catchlight in the eyes that add a bit of life to the person. I would've liked bigger catchlights but that's just a personal preference.
One thing I do notice that jumps out is the framing behind the cosplayer. One of them cuts through her head and doesn't really frame her as well as it should. Just position the cosplayer so that the frames don't intersect her figure and it could really work in your favor.
Besides that your composition is very good, you didn't cropped off any of the joints and have the cosplayer composed nicely within the frame of the image.
Again this is my first critique, I'm just really saying things that my professors would comment on had they given the critique. Hope this helps!