Sometimes it is hard to think of just the right thing to get for an expectant mother.  Here are some ideas:

Dog treats- If she's got a pet, the pet's going to be adjusting to new life too.  Along with a treat for the mom and baby, get a treat for the pet too!

Pedicure gift certificate- She probably can't see her toes anymore and she surely can't reach them.  Get her a gift card to the local spa so that she can be pampered.

Photography- If you're good with your camera, invite your friend to come over for a photography session.  You can take pictures of her throughout her pregnancy or near the end.  Edit, crop, and develop the pictures for her and give her some prints.  Frame the best one for her to put up in the nursery.

Late Night milkshake run- If she's not to tired, grab her and take her out for a shake on your tab.

Free babysitting and restaurant gift card- Give her a gift card for two to her favorite restaurant.  Tell her that the card comes with free babysitting when she's ready to get out of the house.  She'll be happy to know that one of her first babysitters is someone she knows and trusts.