[That's part of it too. She doesn't want to open that can of worms until she absolutely has to. But she knows it will come out eventually, she's just waiting for Kol to be ready to hear it in his own time.

As for the second part, however:]

She left around the same time you did. All of you - Elena and Damon left as well. If she's returned now, though, I haven't seen her.