Stop and take a breath. Then accept this ((((HUG)))).
You've been through so much! My heart goes out to you and your daughter. One thing to know is that celiac runs in families, and that quite a few folks have found that there is a connection between celiac (at least in some cases) and autism. Does your daughter show any other symptoms? Maybe you should get her tested too. It would make a big difference for her if she had a firm diagnosis. For yourself, you could either press for more testing or just go gluten-free anyway.
The pain in your shoulder blade area sounds like it MIGHT be unrelated to celiac. Have you ever had it x-rayed? There is a condition called cervical ribs that is a birth defect. I have it. There are short little ribs growing from my cervical spine and they can move and press on either nerves or blood vessels. If I put my arms out in front of me for more than a few seconds (like to play the harp or to use a commercial slicer), the pain is quick and sharp. Anyway, the cndition is fairly common and just like celiac, a lot of folks don't know they have it. It often takes and injury or severe stress to bring it out.
Anyway, I will be praying for you that things in both your personal and medical life start improving right away.
When I first started I couldn't eat salad greens or sweet potatoes. There was no good reason. To this day I still get almost instant gluten-like symptoms from blueberries. Once again, I can think of no good reason except maybe Murphy's Law because blueberries are my favorite fruit. I got the greens and sweet potatoes back and am hoping someday I'll have my blueberries back too.
In the meantime, try not to overthink it. I was convinced that there was something else wrong but it turned out to be that I just needed more time to heal. Another time apples might be just fine for you or some other random food might give you trouble.
One thing I've learned about celiac is there is no logic to the other food sensitivities that may come along with it. We just need to roll with the punches and try again later.
I don't worry about shared facilities unless it's something like a bakery (or a friend's house) where there is flour dust in the air. But even that isn't always correct. I DO eat at a restaurant - a pizzaria of all places! - that makes both kinds of pizza. BUT, they have a family member with celiac so they know enough to make the gluten-free pizza in a different room with a closed door.
Shared lines are a different thing. If a product states that it is made on a shared line I usually put it back. But once again, it depends on what the product is. Ice cream for example. Cookies and cream has gluten, but I'm pretty sure it is easy to clean the vat the ice cream is made in.
The thing to remember is that shared facility and shared line statements are voluntary. Unless we call the company on every single product we eat, we are all likely to be eating stuff made in shared facilities every day. I've been lucky enough to have only been glutened once in three and a half years and that was from cookie crumbs at my own store. There is no more food allowed in my store now. Problem solved.