Traditional herbal pairings

I am a little confused about the traditional herbal pairings listed at the end of our lessons. The adrenal trophorestorative pair is licorice and dandelion leaf. What is the help in giving such a strong diuretic? I have a friend who is getting terrible migraines and I think it might be from a reactive hypoglycemia from an addiction to coffee. I want to help her restore her overworked adrenals, but would dandelion leaf be ok to give with migraines? Thank you.