In my opinion, Juliet's brand was the reason she did not accompany Kate to the Hostiles when Kate was going to bring young Ben to them for healing. If she had, and some mishap occured, the Hostiles would see her brand, and probably want to know why she had it, how she got it, and for what crime?
Juliet knows alot. As we have discussed in prior posts, was she a "templeized" Other? If not, why not? I mean they taught her to speak Latin, and she was pretty ensconched in their society. It is unlikely the Others will not let any one live with them for 3 years without being on board and drinking the Other/Hostile Kool Aid. Moreover, she knows about Room 23 and Jacob's list. I find it IMPOSSIBLE to believe that she did not ask who Jacob was and why they have a room out of "A Clock Work Orange!"
What has she told Sawyer in the three years they have been shacking up. Again, wouldn't Sayer ask, "how did you get to the Island?, by the way, why were you kidnapping all those other survivors? Why did you want Walt so bad? Why did you put me in a cage and make me eat fish biscuits? What the hell was that huge Statue we saw in a brief flash? What was that weird room that Karl was sitting in? How stinking old is Richard!!!!" If he asked those questions, and she said "They did not tell me everything"- again, I think i would be a bit peeved. Theories people please?