As someone who just had a baby shower a few days ago, I think the best gift to give an expectant mother is gift cards or cash, unless you know her VERY well. I got many things I love and will be able to use, but I also got quite a few things I wish I didn't, and I can't even trade them in for things I like.

So, unless you know what brands the woman likes or doesn't like, her plans concerning cloth vs. disposable diapers, etc., money is probably the best gift to give her, so she can get what she wants with it.

A truly great gift idea is this though: Before the baby shower make a chart with space for each day of the first couple weeks after the baby's due date. On each day make space for a chore or two, and one meal, and write down the names of volunteers who will take care of those things. For instance one day Mom could do laundry and Brother could bring over dinner, then the next day Sister could take care of dishes and Best Friend Janie could bring dinner. That way the new parents aren't so overwhelmed right away, and they have a little time to adjust to the new baby before they're on their own.