It would be good to have a definite diagnosis. The only way to really do that is with a scope.
For now, I strongly encourage you to get her to the vet ASAP. This disease can be dreadful if not addressed immediately. Once the pups get really ill and lose their appetites, it is often hard to save them. Diet is very important, but they also need medications...usually an antibiotic and steroids.
My Cookie has lymphangectasia. Here is her thread:
http://www.yorkietalk.com/forums/sic...ia-update.html
Maybe there will be something there to help you.
Please keep us posted!