As I said the FIRST TIME you asked, you seem far less than certain your want the dog, than I would like to see in an adoptive home. You did not ask to adopt the dog; instead it seems she was THRUST UPON YOU. So now you POLLING an internet site (inhabited by not only dog people but trolls & children) for help in deciding, whether to keep the dog (or not). GEEZ……..
I think you should return the dog. You are not sure enough, nor excited enough. You REALLY do not “NEED” the dog, especially the EXTRA EXPENSES in such uncertain (COVID) times – as to your household health, and income.
There’s no way to forecast the dog’s long term health but toy dogs often have tooth problems, ACL tears & repairs or slipped patellas (knee caps) & intact senior females OFTEN do develop pyometra which can be life-threatening & expensive to treat, since an EMERGENCY spay maybe required.
However, there are plenty of other homes – who WOULD BE THRILLED (jumping up and down – to get the dog) and that is where the dog should go and probably to a home with NO OTHER pets, so it gets all the time and attention it deserves. The owner can either continue to look for a good home at her leisure or surrender the dog to a local Yorkie rescue, who will fully vet and spay the dog and make sure shots are up to date, and test to make sure that she is heartworm negative & fully groomed and flea free – before adoption and they will carefully screen homes & will likely look for an experienced YORKIE home.
The owner OUGHT to be REQUIRED to
1) Get the dog a complete physical BEFORE placement so you have a good idea of her current health or you ought to do it yourself as a screening process (if you want to pay for it).
2) the OWNER out to spay the dog before she goes to any other home. I will give THREE WHYS to explain why it should be done, ASAP which you can *share* with to the current owner:
=She is VERY LIKELY at age 8+ to get PYOMETRA (infection of the uterus) if left cycling, and it can be life-threatening.
=She can get pregnant, if still cycling (if not by your dog) then anything that can dig under or breed her THRU fencing or on a walk, provided she does not slip out a door or gate and get herself BRED – which happens A LOT!
= Being a Spayed female, means the only people interested in the dog will be those who just want a pet. Yes, there are irresponsible sorts who will intentionally breed her (if it can be done) and IDIOTS who will not be careful and will “allow” it to happen…….