She does not have to justify it, or even mention it. But she wants validation or perspective and in that case yeah, it is interesting to talk about.

I am all "read whatever you like" and that is fine. But there are things more important than books, and this preference is worth examining, not necessarily because OP reads more widely (it is perfectly fine to read just type X of books) but because it might be worth examining if it reflects a bias she has also in real life or not, or even applied to herself (which is the worst kind of bias, when used to punish oneself)