The way Disney Reservations usually work is that they require all of the names of who will be staying in the "room" with the guest making the reservation. If your name is included on that reservation, you will have no problems at all, if not, I don't think you will get ME added. You must have your name somewhere to be associated with the stay on site or anyone can just call and add. Since you are staying in a camper, are they driving that camper to the site? I am not 100% sure on how the camp grounds work that. You might want to ask this question on the camp ground forums, maybe someone there has an answer too..
I know one year I made the ressies in my name & drove to the All Stars from my house, but my friend flew in. I had her name on the ressie and she was able to have ME pick her up and drop her off at the resort. I listed her as a guest in the room with me (which she was).