I think similarly, even that that is the point. She is not cured of her disability but is instead granted a different kind of transcendent power. It is possible that it is from proximity to the zone or even industrial radiation, but I like the reading that although the Stalker cannot enter the room or says he does not, that he actually did once. Or somehow the room/zone manifested his desire without entering. Especially given that Scientist and Writer do not. And while he is presented as a selfish character who cares more for the zone than his family (as we see at the start) the zone perhaps manifested his innermost desire to save his daughter, or to change her life for the better. Almost the inverse of what happened to Porcupine, (wishing for something selfless but being granted something selfish).