We got Stella at 16 weeks and she's doing great--she was quick to learn the ins and outs of pee pad training. I think they have a little more control at that age. We enrolled her in puppy training once she had all her shots and now she's well-trained and well-socialized.
Some breeders will keep them longer if they are especially tiny or prone to hypoglycemia, so it's not unusual for Yorkies to go home later than that. I would definitely get another at 16 weeks or older, as little struggle as possible during potty training is always good
