Weird Minecraft base I found while exploring the END

I just opened one of my old worlds, and I found myself in front of the END portal. I jumped in. Not long after, I found a strange base, but that's impossible; that was my cousin's old base. What was this ancient base doing in the 1.8.8 END? And what's weirder is the fact that she has been gone since Minecraft beta, before the END was fully released. I think she was playing beta 1.9, or something... Out of all the screenshots I got, this was the only one I didn't delete...