What a cutie!
I would guess, from her current age and weight, that your girl is going to be a bigger yorkie, twelve pounds or even larger. However, no one can know for certain until she’s full grown, as individual growth varies. Whatever size, she sounds like a typical yorkie in personality and she should be a delight.
As far as the coat, when you ask whether her coat will become silky, do you mean that she has a cottony coat now? If her coat is cottony now, it most likely will remain cottony. The difference is in the density and texture of the hair, which probably won’t change. If you’re not sure whether her hair is silky or cottony now, here’s a link that describes the difference:
Yorkshire Terrier Hair and Coat