For The Past 4 Days, My 30 Year Old Daughter

For the past 4 days, my 30 year old daughter has had a mild headache in the temple area. When she touches her temple she has pain; akin to pressing on a nasty bruse. She was hit in the head by an elbow about 2 weeks ago but doesn't remember if it's the same area. Something she read said she should run the an ER. Your thoughts please.