Hi Jessi. I see you are in NJ. I'm a Jersey girl too
How old is your Yorkie and where did you get her from? It's somewhat normal for her to shake due to a new environment etc. but as others have said you have to watch her blood sugar. How much does she weigh? For the first year you have to watch for Hyperglycemia. Nutrical is something you should have on hand and take with you wherever you go with her, especially if she is not eating. Also, if she's young (too young) 8 weeks (Sometimes even 10 weeks) or younger the dry food may be too rough for her to eat. Try some boiled chopped up chicken and see if she'll eat it. This will atleast get some food in her tummy. Have you had her to the vet yet? I'm not sure where you're at but I'm in S. Jersey and if I can help you in anyway, please let me know. Elaine