Let me make sure I understand you first....you're saying she won't eat the homecooked meals you're making anymore?? (The ones you described?)
Hopefully there's another reason, but the only thing I can think of is that she may have a liver issue.
Yorkies are 38 times more likely than any other breed to have a liver problem (such as liver shunt (LS) or hepatic microvascular dysplasia (HMVD)). My Bella has HMVD, but she's assymptomatic. She's slightly picky too (and I'm told lots of Yorkies are), but I've been told that sometimes liver dogs won't eat because they are getting too much protein and it's making them nauseous, which that could be why she's refusing / throwing up. Organ meat is especially hard on liver dogs, above and beyond red meats and exotic meats.
My suggestion (least expensive suggestion) is to just try using only egg white (boiled or scrambled) and/or chicken as your proteins AND not using organ meat. Just see how she does a few times with that combo. Still use veggies, and I think it would be a good idea to use oatmeal or brown rice even though you're not wanting to do grains....if you don't, her meal will most likely be protein heavy. Try this combo for a couple of days and see what happens. If there's no change, then we'll have to figure out something else. [Note: When you're homecooking, it's a good idea to have the diet balanced by a veterinary nutritionist. There are vitamins/minerals/etc... that they need that it would be impossible to get from just veggies. Bella has a veterinary nutritionist at Cornell...we used to homecook too!
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Your other option would be to have her bile acid tested if you haven't already....that helps determine if there is a liver problem. That's actually what I would do!!!