Severe Headache After Roller Coaster Drive, Feeling Shaky. Taking Advil. Recommendations?

My daughter went to Wild Adventures today in Georgia and rode a wooden roller coaster. immediately upon getting off the ride, she complained that her head banged all around during the ride and she had a massive headache as a result. The rest of the time at the park she complained she didn't feel well. We got home around 5pm and she slept until 10 PM. She said she is not feeling well still even after I gave her two Advil gel caps at 5pm. She complains that "things are moving", extreme headache and she feels a little shaky. It WAS over 101 heat index today, but she doesn't seem to experience any symptoms of heat exhaustion. She is sitting next to me, coherent, very alert, able to hold a normal conversation and figiding with the blanket and other things to stay busy I guess. Should I go the ER or see how she does? I just gave her two more gel caps for pain. She is 15 years of age. YYYY@YYYY