Is this a sign of brain tumor?

What I don't understand is, being this started so young why a dr didn't set up a cat scan appt right away. My daughter had a migraine at the age of 12. Trip to drs, same day trip to er. They set up ct scan. She was given the all clear, thank God. It's just not normal for a dr not to suggest a scan to see if anything's in there that shouldn't be.