I find myself wondering if Jor-El isn't ultimately responsible for why the Legion knew nothing about her or that she was an important part of Clark's life. They knew about Lana, the football jersey and other details... Yet they didn't know who his best friend was from this same time period. It's both odd and disturbing, as it suggests the possibility that she somehow becomes erased from the timeline.
Or that the Legion came from a future in a different reality.