How is her weight / body condition...skinny or adequate...?
Some dogs really do not like the sound of dishes - so just let her eat off the mat - it's a great solution to that part of it.
I wonder if you should just be constantly rotating food sources throughout each week for her...? Kibble/canned/raw/cooked/fish. Have you tried cooking white fish for her, btw? Most dogs LOVE fish. Super easy to cook, not expensive (cod, tilapia, sole, etc).
Also try sprinkling Parmesan cheese on her food. Use Nutrical daily as a supplement.
Have you tried the prescription Science Diet I/D food yet...? Worth a try for sure.
Oh also, it seems many dogs who are super finicky do like "Cesars" dog food for some reason. Yes, it's not the most quality food out there, but the key here is that is IS FOOD
. If she'll eat Cesars regularly, who the heck cares about the nitty gritty, ya know?!