I don't think it was wrong to say that although I can understand her reacting to it. The statement you made doesn't mean, in my mind that you wish she was tall or anything different but that you find tall women attractive. You don't live in a bubble where you won't see other attractive women and notice! She's naive if she thinks that's even possible with anyone! The only thing I can say to this is that you might have said it in a way that rubbed her the wrong way. I don't think you should be dishonest if someone asks you a question like that! If you were to do what is the alternative and that's lying or avoiding the question, do you think that would have had better results? I don't.

I think following up and making sure, as Lee said, you let her know she's fine the way she is, is what you should do for sure. Perhaps she's not thinking as badly as you think she is about this too, what, with the lack of telling you what's on her mind, it's kind of hard for you to decipher. She should speak up if it bothers her too but I know that's not in your control.

Just to emphasize my point on finding others attractive: what if you were dating someone like say Kate Beckinsale and were in love with her but then Angelina Jolie walked by? (two women I find attractive) Just because Angelina is attractive the way she is doesn't minimize how attractive Kate is, regardless of whether it's about height, weight, size of ___ fill in the blank. They are both attractive and you'd still love Kate just as much as you always did. Idk if this makes sense..