This is just one scenario, of what I would think should be very many scenarios, that better answers the question about how the artifacts got to the seven site, than the Amelia Earhart as the castaway of the seven site theory does.
Back in the 1930’s and 1940’s the United States was a very different country. Most people did not live in the urban areas, rather most lived in rural areas, i.e. on farms or in small villages or towns. When WWII began, many of these ‘farm boys’ were drafted and sent overseas to places like Gardner island to man equipment such as loran stations. To most ‘coasties’ this would be quite a different life style, from pretty much living off the land back home, to a deserted island, thousand of miles from anywhere, temps over 110 degrees every day with no change of seasons, no crops to till, or livestock to raise, no ‘real food’ just stuff out of a can or packet, milk and eggs in powder form….. After many months ( or years ) of this kind of existence I would not be surprised if some coasties, ( whether legal or illegal ) took an occasional ‘overnighter’, or a day or two of “sick leave” which meant grabbing a canteen or two of water and getting back to their roots by leaving the base and going out exploring the island and living off the land, and eating real food, i.e. fishing, catching and eating turtles and birds, and even real eggs. (We know the coasties were at the seven site by the ammunition casing we have found) One coastie may set up a camp with his kitchen here ( fire for cooking ), his relaxing area over there, and his sleeping area in some other place. The next coastie (s), may very well set up camp in the same general area, but with his fire area over there, sleeping area here and the like. It seems to me that would explain the many ‘fire areas’ found at the seven site at lot better than one person ( the castaway ), changing her camp setup so many times. I would think most people would agree that common sense says that once you have setup a camp site you probably would be inclined to cook all your meals in the same location, set aside a different area for bathroom chores, and the same spot for sleeping at each night.
Was it only coasties visiting the seven site? I would doubt that, probably settlers also found reason to spend some time at this site, maybe it was the breeze, or the view, or maybe it was just a good fishing spot, or as Gary LaPook suggested, maybe at times it became a lovers lane. Did any of the Norwich City crew visit this site? I think quite possibly, and maybe others that we don’t know of. But many people could have, and probably did spend time at this site and yes they probably lost things, wore out things, and discarded things. All the artifacts that we have found at the seven site could easily have gotten there without the existence of a castaway.
occam’s razor ?