[discussion] Gideon's mother's origin?

Might seem like a dumb question, but I've got atrocious memory and while rereading GtN one thought hasn't been able to leave my mind - in the first book, during the conversation one of the Eight brother (don't remember name) had with Gideon, he talked about her mother being from the Eight. So - was Wake actually from the houses? I had been left with the impression she was originally from BoE. Is it possible the eight necromancer was mistaking Gideon for Orthus, since he was Harrow's original cavalier?