You really think so? You could be right, but if Ichigo sees her walk to Ulquiorra or Aizen and tells them that she is part of their team, I'm sure he will be way too shocked or pissed to bother saying something like that. Imagine how the whole gang would feel... coming all the way to HC, risking their butts, and for what? So that she can join the bad guys. Now this would be good T.V.
You've got a point.