I suppose it could be Marek's, but it doesn't seem like the textbook "range paralysis" version of it. But there are other ways Marek's can manifest itself and then sometimes the bird recovers. I'd check her pupils weekly and see if you see any changes in their reactivity or shape/size as one way of looking for a certain type of Marek's. I've read somewhere that ocular Marek's sometimes occurs when a bird has had some form of Marek's and recovered. Ocular is where the eye greys over, or the pupil ceases to open and close and freezes in one position (dilated or constricted) or simply loses shape (wobbly rather than perfectly round pupil, unreactive).
In the mean time, it's not really possibly to absolutely diagnose non-ocular Marek's without a necropsy - and we sure don't want to go there. So we're shot-gun treating other neuro things. That way if it is a recoverable form of Marek's, she's more likely to recover.