Oh, but lad, there isn't anything distinguishing. You're part of the same mind. No wonder the thoughts get a bit muffled up ("psychologically" speaking). To quote the advice of Pinkie, one of my tuppers:
"Believe what you want."
And the simple way you're supposed to interpret this is that you're most likely going to get multiple answers at one point or another throughout your progress. In a time like that, one of the only things you have left is to simply pick the answer you think is matching her personality, and believe that answer is her; if you get a rude and nice answer and her personality is nice, be my guest and try to guess which answer is most likely coming from her. When you realize what's her and what's not her and you've become used to this practice, everything will proceed much smoother.
My advice is based on this.