Thank you much for the advice!
They do have bowls of the same material. I thought I was on to something because she did eat her full portion when I switched bowls, but then the next day she wouldn't touch it again. Maybe if she was stray for a time she was used to eating just once every few days, not twice a day. She may be finding things to eat when she's outside. We live in the country.
She did eat this kibble before, but then stopped just the past couple of days. I don't think it's the food. Yesterday she was eating grass and vomiting, so perhaps it is a physical upset. She eats my other dog's poo and snacks from the cat litter box. Maybe she has ingested cat litter that upset her stomach. Maybe she's allergic to tomatoes - she grabbed one that fell on the floor.
I can't close her in. She flips out. Any time she is closed in anywhere, she gets frantic, barks, whines, scratches, poops and pees, within minutes. She has something about doors. Luckily my other dog is good about not eating her food, and he lets her eat his food from his bowl if she wants to. I am not sure if he could resist eating her food if she got something different., though, which is one reason why I want her to get used to eating the same food as he does.
Thanks for all your helpful suggestions. I will try them. Every new dog teaches me new things.
D'Elle your dogs are gorgeous!