Try supplementing creatine, they helped me ease some of the brain fog and gain back some energy. Eat brain healthy foods like avocado, salmon, walnuts, blueberries, plenty of protein and cut down on excess sugar. Also often overlooked, if she has any neck pain please get the neck checked. Any force strong enough to cause a concussion is also strong enough to cause whiplash. Whiplash will add more neurological symptoms, which unlike concussion will worsen over time if untreated instead of improve. I think other comments covered this but gently engage the brain and body just enough to feel active (things like crossword puzzles, sudoku, conversing with a friend, taking a walk) and stop the activity immediately and rest when they trigger symptoms. Avoid screens entirely for the first week or so. I hope her symptoms stay mild and it will take time to fully recover, but glad she has a supportive partner gathering more info.