What Causes Headache, Dizziness And Vomiting While Hit On Forehead?

My 31 yr old friend, who is currently generally healthy, was hit on the middle forehead by a soccer ball while we were near the field. She is currently having a headache, a pain at the back side of her head. She also feels dizzy and like vomitting. 4 hours had already passed, and she has been resting since the time she was hit. Are these dangerous symptoms? Or will the pain naturally (and safely) go away in a while?