A reputable breeder does everything they can to insure they are bringing the healthier puppies possible into the world and giving them the best start unfortunately breeders who are not doing health testing are not doing that. I also doubt that she actually has AKC papers because you can make then where they are pet only and by her not doing that and trying to use pet only as an excuse I doubt they even are AKC and this sets you up to nt having a pure bred Yorkie. I have ha basically 6 yorkies (one was mom) none were had health testing and none came from a good breeding and although I was lucky enough to get my current 4 on pet insurance that was not the case with my first and what is worse then the money which I spend thousands upon thousands because of genetic issues she had was the fact of having to watch her suffer and go through so much because of bad breeding. I remember talking to a few veterinarians who were asked about what age to get your dog fixed and about over vaccination and such and how they played apart in keeping your dog alive longer and they all said what actually matters the most is their genetics. Here is a list of what reputable breeders should be testing for
https://ofa.org/chic-programs/browse-by-breed/?breed=YT