M.P.
This is scary. She needs to be evaluated by specialists. I agree that an ophthalmologist is a good place to start. Be sure it's an ophthalmologist and not an optometrist. An ophthalmologist has more medical training and is trained to spot medical disorders while an optometrist is trained to diagnose and fit glasses. If he saw something he would refer her to an ophthalmologist.
I also wonder why they didn't do an MRI or some other extensive testing. IF they did and ruled out such things as tumors, retina difficulties, neurological difficuties, small strokes then you do have to wait and watch. My father had a small stroke that put him in the hospital. The stroke was not visible in an MRI but they still diagnosed it as a stroke based on symptoms alone. It is possible for children to have strokes, bleeding into the brain caused by a blood clot or weak veins.
I assume she stopped the medication which didn't stop the episodes. How long since she stopped? It will take time for the medication to get out of her system.
Later: I don't understand why it's too early for her to see a neurologist. Given your uncle's stress, I'd make an appointment now.