
Hi there, your litter is a little older than mine, my pups were 2 weeks old on Tuesday. At birth mine ranged from4 oz to 6.5 oz. The biggest boy is now 21oz. A good guide is to expect them to have doubled their birth weight by 10 days old, and a weight gain of about an ounce or a little more a day from then for the next couple weeks is usual. 2.5lbs at 3 weeks is defintely on the large size for the breed, and this is certianly why your girl is looking very slim. I would increase her food intake in quantity and qualityto make sure she does not get too pulled down by feeding, no point in worrying about the babes they are obviously doing very well. Are either of the parents quite big for the breed?
bye
Gwen