Ok, so additional SH related things meaning I'm posting here rather than the short-stories board. Silence's grandmother's Shade. She doesn't attack Silence, and never has. Suggests she's able to retain some sense of self, or at least a degree of control.
Was her grandmother able to get some additional measure of Investiture either before or after death? We've seen with Kelsier in SH that Invested individuals with a higher amount of Investiture last longer before moving into the Beyond.
Alternatively, is this something to do with Connection? If you're very strongly Connected to an individual, that persists through death and into the Cognitive (Kelsier was able to speak with Spook, and with Vin).