With most of these, if you don’t see the costume you need, you can email them for custom orders. c: You just need to provide references.
Well, I’ve personally had decent luck with QQCosplay, but they can be hit or miss as far as accuracy goes.
Cosmonde has good reviews, and is said to be very good about communication with customers.
Fan+Friend has some good reviews, and their costumes look fairly nice.
For the wig, this style comes in a couple of beautiful natural blondes.
This style does as well.
Does anyone else have any input for where she can get a dress for Belarus?