Well didnt you say Fae landed on her back? If so, neither of those choices would be a thing, I mean Midnight jumped from the same point Fae fell, and all he did was shatter his ankles although he will be fine, Maybe a cast. But if were talking something that makes sense, I'd say 'Wobbly Leg Syndrome' One of my actual dogs has this condition, where he has trouble walking and standing, since Fae was hit hard in her spinal area, I'd say Wobby Leg Syndrome would be a good call, It doesn't even have to be permanent.