If she asks you what you're going to do, answer as I suggested above. If she presses you, and asks you why you won't tell her more, just say "Because I don't want to right now."
There's nothing that can be said to "I don't want to ..."
What you want to convey is that YOU are beginning to formulate some decisions, apart from her, and that you feel no need to convey right now what those are.
