Tatiana is tiny!
Reading YT for a couple of years, particularly posts from exhibitors/breeders, it is possible to have a perfectly healthy tiny who doesn't grow much. One exhibitor has a tiny who didn't grow at all until her second year, and then just a bit.
Some exhibitor/breeders recommend having BATs and liver function tests done on all Yorkies at 6 months of age to rule out liver shunt. With a pup who doesn't show much growth or weight gain, this would be a good precautionary measure. Many tinies are perfectly healthy, so I don't mean to concern you.
