Well, I don't know much about rabbits, but we had rabbits when I was little and our doe had a littler of four and then had another litter of four about 3 weeks later (not long enough to have re-bred). I think that they can hold some embryos, but I don't know that for sure. Someone correct me if I am wrong. I only had bunnies for a few years when I was young (like 5 or 6) and I just got my first bunny since then 2 weeks ago...
It's possible that now that the kits are here, her instincts are kicking in and making her build the nest and pull fur. some does do it backwards, especially the first time. It's also possible that there are more kits left to be born. Rabbits have two uterus horns, and they can have kits in both. Usually labor in one horn triggers it in the other at the same time, but sometimes there is a time break inbetween. A matter of a couple hours is nothing. Time will tell!