Please do not just pump her full of NSAIDS or assume it is just hormones! NSAIDS can cause more migraines actually called "boomerang" headaches. Taking sugar & caffine away can help significantly. But the only true help can be by a child neurologist. Then you will know for sure what is going on. Is it hormonal, chronic migraine, epilepsy related ( as is mine) or the many different reasons. But please don't just dismiss these symptoms.
I was give naproxen & antidepressants. Told for years it was simply just stress when actually it was epilepsy. My migraines are actually seizure activity related. So I suffered undiagnosed for nearly 30 years until I actually found a neurologist that specializes in migraines.

My neurologist advised me to take Aleve with the triptan. I’ve found that it is more effective than taking either alone.
Also, Toradol injections help me about 60% of the time when triptans don’t. You have to go to the hospital or urgent care center to get them, though some doctors will prescribe them to be administered at home. The shot burns like 🔥 (it is administered in the buttocks) but it can be very effective in relieving the pain. Besides, nothing hurts as bad as the migraine itself, but the first time it can be quite a shock if you aren’t expecting in. Good luck to you and your daughter. It’s bad enough that adults have to go through this but for a child to have to deal with this pain is so sad. Luckily she has a mom who understands and can relate.

There are child neurologists that deal with migraines. Usually at children's hospitals. But definitely needs addressed

Yup only option for me when triptan does not work Advil gel caps work faster. Zofran for nausea. Sleep till I wake up - about 4 hours. Gatorade to hydrate. Reduces pain level but may not get rid of migraine.

Mine started when I started my cycle every month. As a child the Dr wouldn't give me anything either. My mom would give me Tylenol and an ice pack for my head. 😥 Bless her. I know exactly how she feels.