I think you were wanting a general book, and not one just about circumcision.
Still, if you can give her both, then I would give her Paul Fleiss' book "What Your Doctor May NOT Tell You About Circumcision", in addition to whatever general one you have in mind (just make sure that the general one is not neutral on circ).
I would not try to hide your knowledge about circumcision's harms, because unless you step up to the plate and are a definite resource for her, she won't get the point.
If you don't want to buy two books, then I would at least give her the "Should Your Baby Boy Be Circumcised?" pamphlet available at www.nenocirc.org.
It doesn't need to be an awkward conversation. It could just be "when I was pregnant, I just wasn't given alot of information about circumcision. I found this helpful, and thought you might too".
You can also let her know that you ended up doing quite a bit of research about circumcision, and would love to be a resource for her if she has any questions.