If it's migraines it could be a lot of things. My wife used to suffer from migraines, she went to a seminar at our clinic where a neurologist told the attendees about migraine triggers, and that typically migraines result from a combination of different things.
She stopped ingesting caffeine, wears sunglasses outside, tries to avoid loud noises/music, and removed a bunch of foods from her diet. She's been more or less migraine free for a few years now. It's been a real blessing.
I imagine hormones could plat a significant factor, but maybe if some other triggers were removed then your lady wouldn't reach the tipping point that results in a migraine.