My Wife Fainted About 6 Weeks Ago, I Saw It

my wife fainted about 6 weeks ago, I saw it happen. She got up slowly and then vomited. She has had MRI's blood tests and scans. The neurologist won't let her drive for 6 months because of this?? I am highly concerned about this course of action. she is 70 years old and has no symptoms since this occurred.
Her brother had epilepsy as a child, but it only lasted for a couple months. I want her and she wants to be able to drive. Please advise! thank you