Hi there Karla,
Sorry to hear your friend is going through such a scarey time. I gave birth to my DD at 28.6 weeks and she is now 2 and doing fantastically!
I think your friend would apprieciate any gift - as someone else said, it is so nice just to have others trust that your baby will be ok.
Gift ideas: I got a little angel pin that I stuck to DDs humidi crib to watch over her. I also got a little outfit from "earlybirds" the only thing that would fit her for a while (they have a website - just google it - or if you're in Melb the RWH has heaps of great premmie outfits). My sister gave me a bear to cuddle - as I couldn't hold DD for some time. Also ensuring that your friend has transport to the hospital and food pre-prepared for when she has to travel to and from the hospital and wont have the time or inclination to cook food.

I really wish your friend all the best and think that it's great that she has you there to support her - you are obviously very caring and thoughtful.