Wanted to tell you that Equius and Vriska (and possibly Sollux) were indeed the only ones who knew Aradia was dead. That's why Equius made the soulbot, which Vriska wanted to give to her. Sollux is a solid maybe, since he was the one who killed her, but he was being psychically manipulated by Vriska and it was never made clear if she told him or not. Nepeta was the first one besides them to learn that Aradia was a ghost, but only because she was her server player.
Well that clears that up I suppose.
-Mod L