All Yorkies are going to weigh different weights along the weigh so don't worry about that. Actually, IMO, a puppy can not be overweight. Yes, that's my opinion.
As long as you are feeding healthy food and Ellie gets her puppy exercise, I'm sure she is just fine at 6 lbs. I am sure if there were reason for concern, your vet would say something.
So, don't worry
