Its really hard to say unless you seen both parents and even then genetics can sometimes play a part in the outcome of the coat when they are adults. You have a better chance of a silky coat if both parents were silky. When Roxie was a puppy- she looked (still does) like a Ewok from Star Wars.
She has several textures instead of just the silky one. She does have a slight wave pattern directly on her back. But her head and belly are silky. Just like her father. I love her legs the most which are a combination of cotton and silky. She definitely is not a silky coat and never will be but you can use products and the proper tools to help. Yorkies constantly change for years. Some start the color change early and some late. At 10 months mine is still predominately black with very little color change except the top of the head. Sometimes you never know what your going to get.