Not a bad story, but not really special enough to be a Hugo nominee in my opinion.
What was weird was that the speculative element, while quite cool in principle, actually worked against the story in some ways by removing uncertainty in situations where it would strengthen emotional impact. It always seemed to resolve conflicts where real human communications would normally be necessary, and I think that kind of communication makes for more compelling fiction than a rain shower.
On the other hand, the family dynamics was well captured, including the abusive sibling relationship, which is more common than one tends to believe.