I have no idea how long it takes for medication to work, but I wonder if she can take anti-anxiety medication when she feels the attack coming on - or on test days. Maybe on a short term basis until treatments for the trauma itself can become effective. You mentioned the trauma was relatively recent and the timing lines up with increased incidents.
Our natural next step would be anxiolytics at this point, but that's a no-go for other (medical) reasons. So here we are.
I agree that PTSD is a form of anxiety, and that anxiolytics are generally a fine choice for such things, but I don't know what the medical issues are that cause you to rule them out.
I assume that you have already investigated the possibility of taking a year off with the authorities who granted the scholarship? Under the circumstances, they might be willing to put it on hold for a year instead of withholding it entirely.
