The CT is a good idea because it will assure you that there is nothing going on that could cause some bad long term things. For me, getting to a Neurologist was the thing that helped me to come to terms with my headaches and realize that I was OK, just with some side effects.
My headaches are almost all the time as well, they are less and worse at different times depending on the whim of my head or the things that I am doing.

School work is frustrating and difficult, but you have to finish high school (for me I have to finish college). It really helped at the beginning if someone read my books out loud to me rather slowly. It was too hard to keep my eyes open and focused and at the same time understand the meaning of the words. 6 concussions later and a full year since the last one I am starting to feel much better.

For a lot of people, including me, the most frustrating part of the beginning was thinking that I should be getting better fast and it was taking too long and wondering if there was something really wrong (like pooling blood in my brain or something) and the 8 doctors I saw didn't seem to care, and my family and friends did not understand and why wasn't I better yet.
The thing that really helped me to move on with my life was to realize that it might be a long time before I healed and that I needed to find ways to live with that. I have. I live a different life, but it is good and I am going to graduate from an intense 20 credit/semester college in a year. My grades dropped dramatically immediately after I hit my head but they have improved since then.

Basically realize that this might be a longer road than you have hoped, but there is always hope that next month she will be back to normal. The key is finding triggers that start the headaches or worsen them so that she can avoid them. Lastly, don't get another concussion, with every bonk or jostle the recovery time lengthens.

Good Luck! If she needs study techniques just pm me.
Margarite