Also, contact your school immediately and insist they start working on an assistance plan to keep her in school. Her teachers and the nurse need to be aware of the problem, so that they don't think she's just goofing off or being uncooperative when she has fatigue, they need to know that she NEEDS to lay down and rest. The nurse will need to give her her medication, you do know that a child CANNOT hold or take their own medicine at school.

An aide will probably be necessary to help with the schoolwork, if the school had a blind child there, what would they do to help that child? She can learn to be more of a listening learner, instead of a visual learner. An aide or tutor can do her reading for her until this is brought under control. She can do her assignments verbally, and have someone else write them down for her. There are ways to make it work, and your school is obligated to provide them for her.

I would think it most important to get her back into school, with her friends, even if she can't do much of the work yet until you sort the vision aspects. She can listen in class. If the teacher has given them a worksheet, and the class is working silently, then the teacher is free to come assist her and do it verbally.

Also, I find that in order to read, I cover one eye (take off the glasses, as I am also nearsighted, hold the paper close, and put a hand over one eye) and move the paper to wherever is most comfortable to make it easier to see.
Take a plain piece of paper and put it over whatever it is she is reading, so that it is a guide just below the line she is reading, blocking out the lines below. This makes it easier to stay on the line you are reading, as that is the only one you see. (She might need a paper or card with a slit that shows ONLY the line she's on, instead of blocking just the stuff below) A different color paper may work better, instead of glaring white, try a beige or soft blue or whatever color paper for this.

Holding the paper or book to the side a bit, instead of center, may help. Down in her lap instead of straight ahead or on the desk. Help her to find her "happy spot" for seeing. The place where her eyes naturally relax to when trying to read, usually down is easier than up, but she will have her own best place. And she may have to get used to just doing a little, taking a break, do a little more, take a break....

Whatever little tricks you can find to help her work through this, try them, use them, adapt them. Hopefully something I've offered will help her a bit while you and her doctors figure out how to get things under better control.