Hi

Try getting a scribe for her who will write exam for her while she dictates the answer. Check with her college or institution's authorities if she's eligible for a scribe ,make sure you take a medical certificate along with you or enquire if they have any specific procedures.

Its better to take doctor's advise seriously and not strain so much. Try convincing the authorities I am sure some way will come out, Even if she didn't get to write now there is always a next time and maybe next time she will do even more well so let's take this positively.

Let me know if you have any other query and also let me know if your friend got to appear for her exams or not.