Suggest Treatment For Concussion

My 15 daughter got hit in the forehead (between her eyes) with a softball yesterday. She acted fine last night but when she woke up this morning she was extremely dizzy and had a headache. She went to the ball field and when running and warming up she threw up. The trainer they had at the field looked her over and said she looked fine but she may have a concussion, hard to tell because she could be this way for 72 hours. What should I watch for, should she go to the hospital? How do you cure a concussion?