I got my Shayley when she was just over 1 year old and all my other Yorkies took well to her. And out of all of my Yorkies she has bonded closest to me. The breeder I got her from was selling her in the same situation, they held her back to show/breed but she was not in the size range they preferred, being that she weighed just under 4lbs. at 1 year and they preferred to have 5-6 lb.ers for show.
I think you should get her...
