Sorry to hear your DD is suffering with this. My DD, now 10 and also with dyslexia and dyscalculia as well as dysgraphia and dyspraxia, was first diagnosed with migraines as a 6 year old first grader but with a retroactive diagnoses that the terrible stomach pains in kindergarten were probably in fact the onset of abdominal migraines. So, unfortunately, we have indeed btdt.
I would approach it first by trying to figure out what, if anything, can be done to her environment to minimize either the frequency or the intensity of the migraines. Because DH and I both have terrible migraines we started with what works for us - minimizing exposure to fluorescent lights, wearing a cap with a brim to shield her eyes, access to outdoors for fresh air when a migraine starts, the ability to remove herself from an environment that seems to have triggers (ie with excessive noise, too hot, strange smells to name a few. I personally react very badly to certain patterns in clothing, wallpaper or upholstery fabric.) DD always keeps a water bottle nearby too. Her IEP now includes these accommodations.
Getting a prescription for meds to be administered in school was crucial, as was getting the school nurse to follow the orders... We actually had to work with our pediatrician to come up with a step by step plan. First, she could take a walk to remove herself from the trigger, then step outside for fresh air, then go to the nurse for a cold washcloth and/or OTC meds. We even had to establish a time limit for how long she could be in the nurse's office before receiving meds after the nurse decided to have her sit and wait 40 minutes or so while she administered hearing exams to an entire class. (The nurse "didn't believe" the migraine diagnosis and tried every way possible not to follow the doctor's orders regarding the medication. Hopefully you won't run into this kind of complication.) This plan was attached to her IEP. We had to battle to get some of the adults to understand that DD could actually determine what might help. I think feeling like she had some control was important. She has found that drinking Gatorade or chewing gummy bears often helps so she now rarely takes medication. In fact I can't even remember the last time she asked for medication in school.
The public said "it was not possible" to change the lights in her classroom but they agreed to unscrew the fluorescent bulbs above her desk. In her OOD placement they have provided alternative lighting in every room she uses. These accommodations have also been included in her IEP. Preferential seating has also included being near a window for natural light.
DD is on daily meds to control the migraines and we are currently in the process of adjusting them due to cognitive impact (slowing of already slow processing speed, word retrieval difficulties, etc). Sorry - no recommendations re homework we negotiated a no homework plan. I would be careful, though, about setting too strict a time limit on making up work. When DD gets into a bad migraine cluster it can last weeks. A few days wouldn't help. As a kid I used to work as far ahead as I could so that I could take a break when my inevitable migraine cluster hit and coast for a while. Even the thought of reading hurt and even in college I sometimes would put my head down on the desk and write exams with my eyes closed. Now I would know better but back then I just did what I had to in order to get through it. Hopefully your DD won't experience anything this bad but its probably best to try to stay as flexible as possible.
