What a darling little girl she is !!!
But, sorry to say that's not a PB Yorkie. We're going to hear some of the "naysayers" comments on this, but...
At some point, one must rely on Empirical Evidence and can do so through a DNA Test. The Databases for them are growing day by day, and from the one I have used, is absolutely accurate according to the paper trail/linage.
I used:
Dog DNA Test, Dog Breed Test - Wisdom Panel Canine DNA Testing | Wisdom Panel