I had my youngest at 31 weeks after being on hospital bed rest. Babies born from about 30-34 weeks typically do fairly well, although they need to spend some time in the NICU. Once they are able to breathe on their own, it's all about learning to eat and grow. Babies this age are also more likely to get sick (both in and later out of the hospital) and face minor developmental delays later.
The baby probably will not wear clothes right away, so if you look for preemie clothes I would suggest buying something designed to fit about a 4-6 pound baby. This store
sells preemie clothes. I really like the itty bitty zutano clothes, as well as the preemie size kushies. Carters also makes darling preemie clothes.
If you live here in Seattle, you can go to Spoiled by Nana in Madison Park, Merry Go Round in Bellevue, Walmart in Renton and the Carters Outlet in North Bend. All have nice preemie clothes. Gymboree and Janie and Jack also sell a slightly larger (5-8 pound) preemie size that fit our kids pretty well when they went home from the NICU.
I second the advice to buy her a Moby Wrap. Another idea would be a shirt made for kangaroo care. Evergreen Hospital Mother and Baby Boutique sells some fairly stylish kangaroo care shirts designed for the baby to be worn inside. I used these when our babies were at Evergreen.
Another idea would be a thicker blanket to drape over the isolette. Something that is about 45-50" square would fit.