This is the best I can do with the New Moon Companion.
If you want an outfit like the one in the companion you want dark blue jeans, a white vest top and a sorta checked shirt.
Maybe try an Egyptian type wig for the hair as most of these are jet black and come with fringes.
Something like this might work for the scar she has, am thinking the one on the top the longish one, by the looks of the picture in the New Moon companion you would have to cut it so it can be positioned above and below your eye. You would also need to make it more skin coloured as Emily's looks like a healed scar rather than a fresh scar like these. http://www.measurefo...ure.co.uk/-8558
For the prosthetic you will also need spirit gum and liquid latex
Make up to darken your skin I can't find at the minute but there's millions of products out there its just finding the right one. Also you would then need to find out if the make up is okay to use with the prosthetic so you can blend it in with your skin. The liquid latex is needed to seal the lines between the prosthetic and your skin so it all blends in.
I used to get my stuff from a certain website years and years ago but at the moment can't remember what its called. Will find out for you.
Good luck with the costume and hope it all comes together for you.