13 months post craniotomy for meningioma. almost entire thigh, where fat was harvested, is still completely numb. is this normal?

Yes it can be: The peripheral nerves recover at a mm a day so it can take years for full recovery. Thankfully by your description it sounds like it is sensory only so no significant motor dysfunction would arise which portends a better prognosis. There are ways to treat the sensory symptoms if more than just numbness ever arises. Good luck and well wishes.