If she was in the house, couldn't she technically have been seen by anyone else there? The rules as to when ghosts are visible and when they are not have never been clear, but everyone who comes in that house seems to be able to see Moira and there seems to be absolutely no physical difference between the living and the dead in that house, not to mention the fact that they can also touch and carry and move things. Since Violet didn't know she was dead I think it's possible her parents may have seen her after her death. Maybe? I dunno. I don't want to think this too through because I don't expect the show to go in that much nuance about it.
Violet died in the episode after Halloween and I think the doctor said she'd missed sixteen days of school, so I guess it could be around three weeks (depending on whether or not she was skipping school before she killed herself).
ETA: I don't think I'm really answering JerseyGirl's question, now that I reread it. Are you asking how they are going to comprehend that they've seen Violet walking around after they find her body?
Updated On: 12/8/11 at 06:32 PM