Yorkies... you got to love them. It is amazing how different they can be, even litter mates. I have a 5 1/2 moth old who is a bit on the large side (make that a lot on the large side). He weighs about 6.5 pounds already, probably more. At 8 weeks he was 3.5 pounds and at 12 weeks he was 4.5 pounds. His mother was 6.5 pounds and father was 6 pounds and he is already bigger than them. There were only 2 in the litter and his sister was 3.0 pounds at 8 weeks. She has only gained a few ounces a week while my little Snickerdoodle gains a quarter of a pound a week. lol. I think that Snickerdoodle this that he is a Boxer just like his bother and he is doing everything he can to top out at 76 pounds.