I returned to work after 10 weeks and I really liked Sears' The Baby Book (and The Attachment Parenting book for that matter). I think it would be a good choice, and incidentally I gave this book to a pregnant friend for exactly the same reason

I personally did not find Sears to be condescending. It's true, in regard to working he doesn't sugar coat things and tell you what you want to hear just to sell books like many authors do, but I feel like he offers advice to make the best of whatever situation you are in. But I see from reading others' posts that some have a different point of view on this, so I guess it depends on your friend's personality. Personally, I really like this book because it gives "permission" to baby your baby -- to hold them a lot, nurse them to sleep, co-sleep, etc. -- and dispels the myth that these things will spoil your baby. For me, attachment parenting is even more important when I am working because it helps me to keep my bond with my baby even though I am away so much.
Perhaps you could give the book in combination with a couple of others (especially ones geard toward working moms?) if you are worried about how she'll react. I gave this book to my friend along with the Happiest Baby on the Block and another item and told my friend that I liked to give things that we found particularly helpful and hoped that she would find them helpful as well.