I can't really think of any phrasal verbs with "bring" that mean to reveal or to show. "Bring up" can mean to mention a topic. But in this case, "bring out" is very literal. It means to physically carry an item out of the space where it had been enclosed.

Like the other commenters have said, in this context 'brought out' has a really literal meaning (taking something out of one place, bringing it to another). This might be off topic, but a quite commonly-used saying with 'bring out' that came to mind when I read this is 'someone/something brings out something in me'. e.g. 'He brought out the best in me', 'She brings out the worst in me' :)

I think in this context, "brought out" has the implication of showing books that she had. Because when you "bring something out" it's usually with the purpose of showing it to someone. If you aren't showing the thing, you'd usually say "take out". If I say, "He took out his lunch," it sounds like he was probably just going to eat it. If I say, "He brought out his lunch," it sounds like he is with other people and he's maybe going to show it or share it. It sounds more interactive to me.