Technically I only have 1 Yorkie, but I do live with my Mom who has 2 adult Yorkies. My mom's Yorkie's are 7 and my Yorkie is a mere 4 months. So introducing a puppy into the mix has been challenging, since we haven't had a puppy in the house for 7 years.
Also we are running into dominance issues with my puppy and the adult female, they both are attention hogs and they both get very jealous when their mommies pay attention to any other dog.
But its's not impossible, after a couple weeks of adjustment there really isnt' much of a difference. Except there is a lot more love in the house
Good luck!