Hopefully she'll pull fur at the last minute. I used to always gather up some clean leftover nest fur after litters no longer needed it and used it for future nests when does didn't pull fur, but since this is your first time breeding, that begs the question of what you could use instead.
If you can find a place that sells it, you can buy synthetic nesting material made from a cat tails or angora wool (make sure it's chopped up so no long strands can entangle the babies). Vendors at rabbit shows sometimes have them, but this sounds urgent. You could call around your local feed stores and research rabbit supply vendors in your area, or post an ad on craigslist (you may have more luck finding someone who has some angora wool this way).
Does anyone know if, in a desperate situation, you could trim some of of the softer undercoat from a doe and build the nest out of that? Would that be effective?