Welcome to YorkieTalk and congratulations on your soon to be new addition. The suggestion I would have regarding breeders to to interview them just as they will undoubtedly interview you. Spend enough time with the breeder that you get a "feel" for what kind of person he/she is and trust your intuition. If you feel things aren't right, they probably aren't. Visit her home and look at the conditions in which the pups were raised. Ask to see the dam and if available, the sire.
If the breeder you have decided upon doesn't work out, I do know a show breeder in AZ that has pups. If you are planning to show this may be a good match, if not she may have a pup she would be willing to sell as a pet.