Is It Safe To Fly After Concussion And Headaches?

my 15 year old got a concussion from fainting about 10 days ago, she fell backwards and landed head first. She is still having headaches and blurred vision intermittantly. is it ok for her to fly in an airplane 21/2 weeks after incident. no mri yet done going to doctor later

she is otherwise healthy, states she feels better but still having residual effects