Hi,
Thank you for posting your query at DoctorSpring.com.
If she has completely recovered her vision, there is no need to worry now. However, if the symptom of vision loss recurs, then, she would need evaluation by a neurologist to rule out an ischemia (lack of blood flow to brain) or demyelinating illness (due to damage of optic nerve covering). This would require MRI scan of brain and visual evoked potential studies. Both are safe in pregnancy.
I hope it helps. Please get back if you have any more queries.
Best wishes,
Dr. Sudhir Kumar MD (Medicine), DM (Neurology)
Senior Consultant Neurologist