I haven't been reading the Dark Reign comics,so I have a question about Emma. She is a member of the Cabal,but in Uncanny X-Men comics,she is with the X-Men acting nice and perky. Do the rest of the X-Men know that she's in the Cabal?

She is with the Cabal, but the X-Men don't know. At least not yet.

doesn't storm know about the letter.

because wasnt she talking to Emma right after she got it, she basically gave her the idea of joining..

ohh, well i remember her talking to storm, but i don't remember the conversation to good.

the one where storm told her to act like a leader or whatever?

I have a rather wild and crazy theory about Emma's current involvement with the Cabal and Dark X-Men. I'm not going on a lot here and it's mostly based upon character reactions and comic previews that have been released.

First there is the Confession book. Supposedly, it's a double size issue. I despise it when they use the term "and life will never be the same". Every time I read that I could ring someone's neck. Is this going to be good or bad for Emma?
If it's positive I will be all happy. If it's a negative turn I will more be thinking, "wont someone not rid me of this meddlesome writer?" (Not serious, and bonus points to anyone who gets that reference.). I can only stomach this Black Queen affair for so long.
It's even more irritating when I feel that Cyclops has just as much to apologize for. There is some serious irony in how Beast, before capture, talked to both Scott and Emma that he will be talking to them both about their clandestine actions. This seems fair to me about how Hank knows that both of them are in the wrong, no matter their intentions; and need to sit down and talk this out. Though if he thought it was that imperative and urgent, why did he put it off? It's interesting how it seems that before this conversation happened that Beast is captured.
I am wondering if this is true though. What if the conversation did happen? Could the Confession book be a post dated story. As with the Dark X-Men: Beginning. That may seem unlikely when you look at the over the top cover image. Emma is in her Black Queen(pains me to even type that) costume. Though that could just be misdirection.
I'm just finding Scott's reactions to Emma's to be a trifle underwhelmed, at least in front of his X-Men teams still with him. Even telling the shocked Colossus that he has an idea of what she's doing.

I mention this, because I was looking at the dates of the releases and rethinking some of the issue summaries Marvel has released.
I noticed that the Confession book is released the week after this still classified Uncanny X-Men # 515. Even part of the Confession description is still listed as Classified. As if there is more that aren't saying just yet. The current statement they use is plenty.
Then there's the matter of the issue summary for the the first Exodus book, that is released the week before the Uncanny X-Men # 515.