There is a type of headache called a cervicogenic headache that sounds like what your friend may have. Often, when trying to diagnose this type of headache, a doctor will press on different parts of the neck to see if it triggers a headache.
It has lots of possible causes, including pinched nerves, eye strain, fatigue, stress, injury, or certain medical conditions. https://www.healthline.com/health/headache/cervicogenic-headache#causes
Since they are new for her, she should see her doctor to rule out anything serious.
I assume she has googled "migraine" to understand it better? Yes, migraine sufferers often report that their migraines seem related to hormonal swings. Yes, a migraine can have an aura. Can she see a doctor who specializes in migraines? It could help a lot.
Magnesium and vitamin B-2 are recommended for migraine. If she has never taken magnesium before, she should first cut the tablet in half for the first few days and only take half, because it can give some people the runs. Once she's sure she can take it, she can move to taking 500 mg magnesium and 400 mg of vitamin B-2 daily. One article I saw said to take it for at least three months to see an effect; my doctor recommended it and didn't act like it would take that long to be helpful.
I have also seen the recommendation to take 150 mg. of coenzyme Q10 (CoQ10) along with the magnesium and B, but other articles say it takes at least six months for CoQ10 to help, and when my doctor recommended the magnesium plus B-2 she didn't mention anything about CoQ10.
That all said, however, if she can simply press her neck and get a migraine, in her shoes I would not just assume taking vitamins will solve everything. She should certainly see the doctor.