We got our first puppy (not a Yorkie) three years ago from a pet store before we knew ANYTHING about how bad pet stores were, we just assumed that's where everyone got a puppy from

. We were not looking for a particular breed , just something that the kids would like, didn't get to big, and "little-shedding" . So we never even considered a breeder because we didn't want a particular breed of dog. We got lucky .Our Sydney turned out to be a great dog. But since then I have learned much about pet shops, byb's , puppy mills...that I would never buy from there again.
I have friends and family that still buy from pet shops even though I have told them and showed them what I learned...Not that I'm an expert , but hey I can back up what I say now......and they still won't listen. They all say "Well this pet shop gets there pups from reputable breeders

I try to tell them but they would rather listen to the 16 year old behind the pet shop counter who has been working there for two days ! But I digress.....
That long winded rant ( I tend to ramble at times

) was to tell you that I understand not wanting to leave her , and falling in love with her despite it being a pet shop.
As long as they love Kaya , that should be enough. You didn't do anything with the intention of hurting her. And if she was that worried about your choice , maybe she should have taken it upon herself to do the work. Sorry, not trying to sound to mean...And from what I'm getting from your post she only wanted a Yorkie for "status" or to have people look at her....well then she deserved what she got , because wanting to be like Paris Hilton isn't a good reason to get a dog !Again , sorry...
Stop beating yourself up. You didn't do anything but give them a puppy they love , and what is wrong with that !!!
Ugly puppies need love too