Hopefully, if your friend has suffered from seizures in the past few years she has been seen by a neurologist.
If not she should ask to see one. It does depend on the type of seizure she is having but the neurologist should send her for an MRI scan which is a far more sensitive imaging method than CT. A CT scan can show if it is a tumour causing the seizures but if it is a small change or defect in the brain that is the cause, MRI usually gives the answer.