It seems more like a case of vertigo, but because of the bad migraine and also with history of diabetes it is important to rule out certain other causes of dizziness
that might mimic vertigo.
It is also important to know detailed drug history and history of any head injury
First of all before coming to any definite conclusion , I would suggest a couple of investigations:
1. Complete blood count
: To rule out anemia.
2. Blood sugar estimation : Fasting and PPBS. ( Especially if your mother is on insulin to rule out hypoglycemic episodes )
3. MRI Brain ( Because of worsening headache to rule out any CP angle lesion . In migraine scan would be normal)
Also check her blood pressure ( lying and standing position) to rule out postural hypotension
With this investigations ( considering the reports are within normal limits ) we would be able to rule out other causes and come to a definitive diagnosis of vertigo ( benign paroxysmal positional vertigo in which dizzy spells usually follow change of position ).
1. Bed rest and avoid precipitating position.
2. Oral cyclizine
You need to see a doctor for detailed clinical examination.
See a ENT doctor especially if there is associated hearing loss
, tinnitus or discharge from ear.