Welcome, Roland!
It's been over a year since i saw this . .didn't Angie get pulled into 1897 by Quentin and his buddyEvan Handley's over curiosity . .not Barnabas. . ? They cunjured her up at the caretakers cottage...
No, it was definitely to deal with Barnabas. My own explanation for Angelique's presence in the original timeline is that Quentin and Evan must've found some other reason to summon her from the flames. After all, Evan came up with the plan to conduct a ceremony to call someone from the netherworld very quickly after Quentin proposed that they needed to do something about Barnabas.
But if Angelique had been Cassandra in the '60's wouldn't she have known all about Quentin and how he would die?
I think that's an excellent question.
The timeline for Angelique (so far; 1840 screws it up) goes like this: 1795 to 1968, back to 1795, to 1897. The proof that she existed already in 1968 is that...
[spoiler]in 1897, she knows David, she recognizes Julia, she knows Chris' secret, she reacts when called "Cassandra", and she flat out admits that she was there previously. Wouldn't she have known about Quentin's ghost?[/spoiler]
It just feels to me as if the writers hadn't fully thought-out the implications of what they were doing (a rarity, actually, for the DS writers).
I agree with Magnus Trask that it happened more frequently than that. Angelique's history is but one more example, but that's a subject for another topic.