Hello and welcome to YT! I wish you all the luck in the world in finding your new baby. I did want to make mention that a breeder letting a pup go at 6 weeks of age would throw up a red flag for me. Most reputable Yorkie breeders will not allow their pups to go to new homes until at least 12 weeks of age as it much better for the pups to be with mom for proper nutrition and socialization. I hope this helps.
YorkieProud