However, it makes perfect sense to me that Sarah, in a seance, would have been able to inhabit Victoria, and put her through a sort of time-compressed dream, taking her personally through the whole story of how Barnabas came to be, as if she'd been there herself. Sarah would have thought this was a story that had to be told for the sake of everyone involved, to stop further murders, and to make Victoria and perhaps the Collinses aware of what a good man Barnabas started out as, so they could not judge him too harshly. I think it's very possible that this was the original intent.
Sarah just exchanging one governess for another across a couple centuries makes no sense. (I don't know the latter half of 1795 or 1968 though.) My little theory doesn't account for the governess-swap though. A dream during a possession wouldn't account for Miss Whoever popping into Victoria's seat in 1967.
This scenario would have led to Barnabas's rehabilitation as a protagonist whose past was known and forgiven by some of the "present-day" characters, at least... more than just Julia.... this may have been considered too much to expect from the family.
