The migraine medicine imitrex is an altered version of DMT, but I don't know if DMT has the same effects. Imitrex is an abortive, but I don't think it has preventative properties. Migraines can be triggered by a lot of things, including stress and muscle tension. My shoulder and neck muscles sometimes get extremely tight when I smoke DMT. As a matter of fact, I developed chronic tension headaches after smoking DMT. I had a lot of other stuff going on in my life at the time, so I can't say that dMT caused the headaches, but it definitely trigged them and I had to stop partaking. (it's been over a year since I've been in hyperspace. I miss it.)
Maybe oral would be better, I've never done pharma, but I've been given the impression that it is gentler. I think blasting off is one of the reason people get neck and shoulder tension sometimes. Maybe the slower come up would do away with the muscle tension and therefore be a better option for your mother.
Sorry I don't have more info, maybe someone here will know if DMT can be used as a migraine preventative. Good luck. Headaches suck.
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