I just wanted to say congratulations! I have no idea how to introduce a new yorkie into your "pack", but I am sure many here will know what to do. We got our female yorkie, Trixie, a year ago and she is a doll. The only real big difference I have noticed from my first yorkie, Biscuit, who was a boy, was that he was very territorial and she is not .... oh yeah, and of course, no marking from Trixie
Best of luck to you....please post pictures.!