I'd second Bugsy and Chiara's recommendations, they are my two favourite books and I always find them helpful. While pregnant, I also enjoyed the fairly silly book by Vicki Iovine, "The Best Friend's Guide to Pregnancy". It's very Californian - but funny, honest and tongue-in-cheek. Bloomsbury's 20-second attempts to anglicise it just add to the fun.
I didn't find anything written down on breastfeeding terribly helpful in the end, I have to confess. Personal support from friends helped me more.
Titles I would be cautious about if she is a nervous mum to be:
What to Expect when You are Expecting, also American (because it is just a bit too informative, I immediately thought I'd got every complication listed!)
and a book by Gordon Bourne on pregnancy which was given me by a well-meaning acquaintance. This is basically a medical textbook. I think it might be useful if one were to suffer some kind of problem in pregnancy, because it is detailed and comprehensive, but boy is it scary if all is going well.
I hope all goes well for your friend Alex2!