Re: Violent vomiting
Sorry to hear about your mother. If your mother is a bit older it is probably wise to make sure she has a full check-up, bloodwork etc. to rule out anything unpleasant.
However, what you describe sounds exactly like migraine. Much of my migraines as a child, and even now, occur without headache but include nausea and vomiting. Migraine without headache is very common. It can also be easily treated with abortive medications - in fact that is one very good way of determining if the diagnosis is correct. Abortive drugs such as sumatriptan (Imitrex) can abort a migraine in progress in most cases.