I thought that at first. But if that's the case, she should already know it, because isn't she in prison for that murder? I would assume that if it was she, however, that she was doing it on the Doctor's orders and with his knowledge - since otherwise, how could it happen, and he walks right into it, etc. And it has to be fixed, because otherwise they could never recast him.

But in any event it didn't seem to me like she knew *all that* (like, that she had killed him, that she was going to kill him, that he had asked her to...) But who knows, timey wimey...