My Mylee is a Silky Terrier. Both her parents are the AKC standard 9-11 lbs but she is barely 7lbs. Other than her weight, she is ALL Silky Terrier by appearances. For me, a true Silky and a true Yorkie do look different (as adults
) but many people have mixed the two and the offspring of these mixes are harder to differentiate. Most people I run into call her a Yorkie, but many people here (my area in KS) are not aware that there is a separate breed known as a Silky Terrier because they are less common. I continually watch the classifieds in my area and notice a couple of Silky advertisers say their babies will be "small" 4-6 lbs fully grown, which we all know they cannot guarantee, and it makes me highly suspect, but shows people are breeding them off standard too. Also, I believe when some refer to a Yorkie as "Silky" they may be referencing the type of hair since many call thier silky coated Yorkies a "silky." I ran into a lady the other day who commented on my "Yorkie" and said she has two Yorkies too. When I told her Mylee is a Silky she said her Yorkie is a Silky too.
OP your baby is adorable and no doubt will bring you many many years of joy.