Thank you for your question. Although without being able to examine her I can not offer her the specific advice on diagnosis and treatment that she needs, but I would try to provide you some relevant information about her health concern.
Although hypertension could be the reason of her severe headache but it is quite essential to rule out the possibility of migraine here. The mainstay of the migraine treatment is always to identify the triggering factors and to avoid them. Triggering factors could be different foods such as cheese, chocolate, alcohol and even few fruits. Other factors that may induce your migraine attack may be contraceptive pills, stress or depression, bright lights, loud noise and traveling. Few women experience headache more commonly during the time of their menstrual periods & at the time of hormonal imbalance. I would suggest careful record of events that have proceeded with the attack and avoid those factors. In addition, suggest her to rest in a dark & quiet room, meditate, have a balanced diet and avoid taking unnecessary drugs. Even then if she suffers continuous headache, please arrange an appointment with a neurologist right away who will evaluate the further underlying disorders here that may be the main reasons of your migraine attacks (if she has) or hypertension and can provide her an appropriate treatment. Hope this information proves helpful to you.
Take Care & Regards!!!