Thanks for the great advice! I have a lot to read through here.
She's been eating well today on the all-dry food. I'm going to take her for a walk in a little while since she last ate around 1 and is napping right now.
There are two doctors at my vet's ofc. The main doctor (1st visit) wasn't worried about her weight and even said she just might be little as an adult but wanted to see her put some weight on those bones so he couldn't feel them as much. The other, younger doctor on this last visit is the one who scared me.
When I got her at 11 weeks she only weighed a little over 1.25 lbs and at 18 weeks she's now 2 lbs. Not a big gain but I can tell she's grown since she fits in sweaters that were too big a few weeks ago.
If she doesn't throw up by the end of the day I'll give her some minced chicken tomorrow afternoon so I can keep an eye on her. If that goes well then the next day I'll add some rice and give that to her at night, too.
Again, thanks! I have SO much to learn so it's nice to have the help and suggestions of other Yorkie owners like yourself.