The fact that you are so supportive is so great! My parents were very supportive as well, especially my dad. One thing he did for me when I was little is that he bought me a stuffed animal, a puppy (that I still have) and sprayed the cologne he wore on it (if you wear perfume that would work or if not that's fine too I am sure). He told me that Darby would keep me safe and if I hugged it, it would make me feel better. So I had it with me in my backpack and would take it out if ever felt like I was going to panic. It really helped, and still does (and I am 22!). Also, be sure that her teachers are aware of the situation she's in and even give them resources so they can familiarize themselves with it (they are teachers, they're supposed to do things like this for their students).
Hope this helps!