Migraine can cause intermittent blindness in some people. First thing is she needs to be treated for these attacks and also prophylaxis treatment for these migraines will prevent development of these attacks. Simple other things are if there are any trigger factors known , those have to be avoided. Avoid excess caffeine,chocolates etc and catch good night sleep. The fact that your father has had berry aneurysm, there is genetic predilection in her. but there is no standard protocol to screen all family members unless there are symptoms and signs indicating these aneurysms. She should get treatment and prophylaxis for her migraine. If well controlled with out any headache, you needn t have to think much about aneurysm as could only have migraine. Kindly screen her blood pressure for the record. As high BP could lead to rupture of aneurysm if any present. I would like mention certain symptom and signs of aneurysm rupture for future cautions. They are sudden worst headache ever, with nausea and vomiting, neck stiffness and pain, vision disturbance etc. In which case she needs immediate attention in ER. Regards