Thanks for the replies. I googled around and unfortunately didn't find any vet colleges near me.
The food allergies would make sense. Some of her other symptoms (though I can never tell if it's related) are dry flaky skin and a dull coat. Over a year ago, she also had weird issues with her ears. They'd get very dry and the tips would be black and crack and bleed (a lot!). The only thing that ever fixed it was me putting coconut oil on every day. But she's had skin problems for years. Could an allergy build up to affect the stomach?
Issue is that she was on kibble (innova evo) before and when the skin problems started, I switched her to the homemade diet.
Originally it was lean beef, sweet potato, mixed vegetables (frozen, puréed), and eggs. I then switched her to the chicken diet. I even fed her ostrich (!) between those to try and rule out allergies. The diet change helped her skin a bit. Her hair grew back where she was balding. But it's still very dry and dull.
But because she's tried so many proteins, I don't know what I could switch to! She doesn't like fish. And I can't afford a diet of lamb or some other expensive meat.
I know a good next step would be allergy tests. But that's more money, and will possibly show no answers again... But I worry everyday that something is going undiagnosed that could be harming her more and more each day. It's incredibly stressful.