I think she has a hard time comforting someone since she hasn't experienced being comforted before. So when you asked that from her, maybe she felt like she doesn't know how to go about it. She cares for you yes, but is just awkward in showing it.
Ooorr, another scenario could be she was dealing with something and couldn't feel bothered to worry a...... reply
This really isn't like a response to your text, I'm just going off a tangent. I'm not that open about me being bi, but when people ask me, I tell them I am. But somehow I sometimes feel that I'm lying? I don't know how to describe it. Like I like guys and women, but then I realize that I just like people regardless of their gender. I just feel like...... reply