Hello, My 7 Yr. Brittney Is Loosing Her Balance, Throwing

Hello, my 7 yr. Brittney is loosing her balance, throwing up and drooling excessively only once day in the evening for the past three days. she is normally in perfect health. Saturday she jumped from out boat onto the blacktop while moving approx. 20 MPH (I was with her from the boat launch to camp-spot). and this started a couple hours later. Could she have bumped her head to cause a concussion? And what should I do?
Thank you.