I guess my concern would be the differences in personality. Does your little girl get along well with other dog breeds? Poodles and Doxies are not nearly as high energy as most terriers. That could be a good thing if you want a dog that will submit to your little girl. I guess it could work as long as your girls is not to pushy with the pup.
I know there are Yorkie breeders in Pa. I guess it depends on what kind of breeder you are looking for. If you go to the AKC website and do a search for conformation clubs in your state. Each club has a breeder referral person. Those clubs are usually quite particular about who they will refer to. The breeders often have pups they will sell as pets although sometimes you may need to get on a wait list. Of course always do your own investigation as well.
American Kennel Club - Club Search and Directory