Well, but I think, she won't really continue to go down that road. She has changed too much, that's why she saved Marian and changed her master plan twice this Episode. I think she is on edge and the question now is, which way she will continue to go down, evil or good... She has never needed to sit something through not even with Daniel since Cora interfered back then. But now she'll have to lean back and wait and see what will happen. She has to trust in true love and that is what all this is about now. She knows that Robin and her are true love and the obstacle they have to overcome isn't just Marian, but herself and her way of thinking and reacting. She is just trying to do what she has done in the past and tries to ignore that it hadn't been helpful and good for her back then. But I guess, she'll realize that everything that has happened in the past has brought her to a Point where everything is good for her (except for Robin) I mean, she already was at a Point where she had to admit that her relationship with Henry was anything but good and I believe he can help her to overcome all that Trouble. Not to mention the rest of the town who hated her until she came back from NL with the rest of the "gang".
I don't know, I just think that everything that has happened to her in the past seasons and has influenced her to the extent that she has been able to use White Magic and seeing her half sister screwing up wasn't for nothing. She won't continue to go down that road. If she does, she is more lost than I ever believed she was. ....