I have a tiny one. She is 4 months and still not quite 2 lbs. yet.
She is completely healthy...just very small. Like you, I knew in advance
that the puppy I had chosen was going to be small. Her breeder warned me that Callie was a very picky eater too, and I had to wait a bit longer before I got to bring her home. But it was well worth the wait. She is FULL of energy and such personality. I have been very careful with her...making sure she eats right and stays current on her shots and vet visits. But her tiny-ness has not hurt her at all!!~~ She is just perfect to snuggle with and tuck away in my purse when I got shopping~