Michelle gave great advice. Unfortunately what often happens in situations like this is that friends stop "hanging out" with the young woman and she then not only faces becoming a mom at a young age, but she ends up facing it alone.
Shop with her for baby things. Perhaps if money is a problem, look in to places that can help her (such as a Crisis Pregnancy Center or Catholic Charities) with needs such as a car seat, clothes, etc. Offer to help her set up a room for the baby, or a place in her room for the baby.
Its wonderful that you are already thinking of ways to help her. She has a good friend.