I don't really remember the context of where I read this story. It could have been online, but, if so, it would have been at a notable site. It may have been in a collection, too. I think I read it between 5 and 10 years ago, but it may have been earlier or later. It was either a longer short story or a novella.
The story concerns a space station in orbit around the Moon. The orbit of the station has been decaying, and it will soon hit the surface. Already, it has gotten quite close to the surface.
A young girl is living on the station. She has been living there alone for many years. Everyone else on the station died some time ago -- due to a plague (bioweapon?) or fighting, or both, I think? The girl has a companion of some sort, either a stuffed animal or a robot, I believe.
I think there are some people who discover the girl is living there not long (days or weeks) before the expected impact. They make an effort to rescue her, I think, but there may have been some complication due to the fact that the station was believed to be still infected by this plague. I don't recall whether she ended up being rescued or not, but if I had to pick, I would say she was, since I don't remember it being a particularly dark story. I could be wrong about this, though.
I can't remember much else about the story, but this premise seems unique enough that it might suffice to ID it.