Does she know she's not real?
I was stuck at first, but answered. Will tell answer when you tell me what you'd have said...

I'd have to answer "No".
If she's not real (and who are we to decide) then she knows nothing, and so cannot 'know' she isn't real.
If she is real (She is the butterfly, we are the dreamers) then she cannot know that she's not real, as that would be untrue!