Having trouble with sleep

My sister 36F, asian, 4'11'', 139 lbs has trouble sleeping in the first phase of night (10 AM to 5 AM), however, she does not have any trouble falling asleep after 5 AM. What could be the factors affecting this pattern? Vegetarian, no consistent physical activity, has 4 oz of tea with milk in the morning before 11 AM which is not caffeine heavy at all. No history of anxiety. Possible PCOS but never diagnosed. Vegetarian - no eggs. Taking multivitamins, omega-3s, vitamin D.

Any thoughts or tests that I need to get done at my primary care?