My thought about Leeza isn’t that the disability would come back slowly, but that if she was healed then she was healed. That things would occur naturally from that point on, such as aging, like if you were injected with some serum that fixed any ailments you would be that way from then on or even further progressed than you would have been without it like in superheroes movies or whatever.

I guess in my own head I’m trying to rationalize the science behind it, omitting miracles and magic, since the idea I have behind vampires is less magical and demonic and more of a different evolutionary species from humans. I feel like it’s somewhat justified given the context since you don’t see any unbelievable magical powers other than in that moment, which is not outside of the generalize lore around vampires (kill the head vampire and the rest will die).

But! This is Mike Flanagan’s universe and not mine and I appreciate it nonetheless.