Did they check for BPPV? If not, time to consult ENT physician. Meanwhile stay hydrated and suggest her to take trial of T. Vertin 16mg thrice daily for 5 days to see if it helps.

this may be Syncope due to dehydration & hypotension or hypoglycemia or due to mentally sensitive ness to tempreature (sun stroke) leading to vaso vagal tone disturbance leading to transient, self-limited loss of consciousness with an inability to maintain postural tone that is followed by spontaneous recovery. This definition excludes seizures, coma, shock, or other states of altered consciousness. Although most causes of syncope are benign, this symptom presages a life-threatening event in a small subset of patients. Presyncopal symptoms reported may include the following: Prior faintness, dizziness, or light-headedness (70% of cases of true syncope) Prior vertigo, weakness, epigastric discomfort, nausea, blurred or faded vision, pallor, Red flag symptoms: Exertional onset, palpitations, severe headache, focal neurologic deficits, ataxia or MIGRAINE CLUSTER HEADACHE. AGGRAVATED IN SUMMER TEST. VITAL sign ECG CXR ROUTINE BLOOD TEST CTSCAN BRAIN EEG SOS. TO DIAGNOSE CAUSE if all test involving CT SCAN BRAIN IS NORMAL. yet suffering Homeopathy biochemic has good scope in medical condition of no cause avoid direct sun exposure wear sun glases for eyes scarf. for head remain hydrate take water intake in summer 2L have full healthy diet salad vegetable menses irregularity if any may also lead such carry choclate avoid hypoglycemia