At 7 months, a damaged nerve should be showing signs of functional return. The patient needs and evaluation. Hope is not lost but it's time to start worrying. Contralateral Botox can offer temporary symmetry but the frontal branch of the facial nerve might require repair.
It is possible, at this point, that brow movement might not return on that side. It is not unheard of for movement to return at 12 months or even later but that is uncommon. Your options include using Botox to soften the movement of the normal side vs. having a browlift procedure to lift and reposition both eyebrows to provide more symmetry. I hope this information is helpful.Stephen Weber MD, FACS