I wouldn't recommend Excedrin as it contains aspirin. I had to stop taking my migraine pills when I got pregnant and while they were horrible at first- my dr wrote an rx for Tylenol with codeine to try and control them... they've actually died down for the first time in over ten years.
Suggestions:
Try and find the cause- the fastest way to cure/treat an illness is to eliminate the cause. (granted this doesn't always work as you may still have after effects) If she needs a nap- take it. If she's dehydrated- drink something (preferably Gatorade or something to replenish the electrolytes.) If she needs to eat- eat!
Showers. I used to shut the door in the bathroom- have my boyfriend check on me every few minutes and then curl up in the shower until the headache went away or the water got too cold. The upside/downside being if you puke! Hey- all clean :)
However sometimes things can't simply be fixed by a good meal and a nap. Stress is a part of everyones daily lives- she can try reducing it (if possible), having her so or family member rub her back, etc.
If this is a new thing and it doesn't end pretty quick like- I think you should recommend she visit her doctor. Headaches/migraines can be indicative of an underlying concern from high blood pressure ranging to cancer. Or it could just be all the extra hormones.
Good luck and let us know how it turns out