I hate sounding harsh, but, Rebecca is easily one of my fave YGO characters, and if you hadn't labeled the pics, I never would have figured out who you were! Can you put up a reference pic? I'm familiar with the outfit she wears in her first appearance, and that has a pink / teal jacket, over-the knee stockings, and boots.
I like your pigtails, but a blond wig would help the costume, especially since her clothing is civilian. Katie Bair has an excellent tutorial for parting wigs at http://katiebair.com
Being super-nitpicky here: your teddy is the wrong shape and color. Plus, he wears little teal overalls.
I am happy to see that someone attempted Rebecca, but your costume needs a lot of improvements.