What Happened to Meg's Sister?

While most of the questions we ask here are a bit tongue-in-cheek or involve events that would have taken place after the series ended, this one was a real hole in the story line that bothered us from the beginning. Perhaps the whole story of the way Meg's parents treated Grace was simply foundation to ensure that we were 100% on Duncan's side when he "kidnapped" his child and left the country...but what about the victim?

For a moment, Sheriff Lam gave us the impression that he was going to do something to help Grace. We learned that he'd been an abused child himself, he discovered the secret closet in which Grace had been kept and he had his eye on the house.  But then...nothing. By the time Duncan disappeared with Faith/Lily, Lam appeared to be back in the Mannings' pocket and to have forgotten all about the haunted child they kept locked up in the dark.

So Duncan rescued his child and ran away to Australia, and that was great.  But so far as we know, Grace is still locked in the closet.  Lam knew about it. Duncan knew about it. Veronica knew about it. Veronica belatedly told her father about it. And, it appears, they all left her there and went on with their lives.

Maybe the title of this post should have been "What the hell is wrong with the people of Neptune?"

I kind of hope Grace comes back and kills everyone at the reunion or something.