Ok, let's recap here:
According to everything that's been posted since my last post, this should be the semi-correct (fully correct, unless I omit things which I tend to do sometimes) timeline for Angelique:
If I may, here's a slightly different timeline for Angelique:
1692 -- The young servant Miranda DuVal testifies against Judah Zachery.
1774 -- Angelique Bouchard is born in Martinique. There is evidence to support that she is a reincarnation of Miranda.
(Angelique and Barnabas did not fall in love, btw. He clearly fell for Josette, and it's debatable that what Angelique felt was really love.)
1795 -- The former servant to Josette becomes Angelique Bouchard Collins. She has some powers, but doesn't always have control of them.
(Barnabas did not kill her by shooting her. She survived the gunshot, only to be strangled to death by him in the coffin room. Ben buried her body in the woods.)
Now in spirit form, she appears to Ben as a disembodied head and later testifies at Vicki's trial but is able to disappear at will. For some reason that is never explained, her body disappears from the grave.
She is then banished to hell, but her spirit remains bound to her portrait.
1968 -- She arrives as Cassandra Blair, a graduate student at the University of Rockport, and marries Roger (after he takes off with her portrait, which Vicki brought to Collinwood). She eventually loses her powers, then regains them after Nicholas' destruction. She visits Elizabeth as Cassandra in a dream and again in the flesh, then is banished to 1795 (not 1897 as you wrote, at least not yet)-- at the point where her 1795 spirit was returned to hell-- as punishment for mistakes made in 1968. She is burned by Ben and returned to Hell. As time passes, her desire to return to Earth increases and she asks for Diabolos' forgiveness, and they strike a deal in which she can return with her powers intact if she can make a mortal man fall in love with her (but without the use of those powers).
1897 -- She is summoned through the fire in a black ritual. Toward the end of the 1897 storyline, she disappears.
1969 -- She becomes a successful model, meets Sky, and takes his last name.
1840 -- Angelique claims to have wandered the Earth for 40 years, and obviously has no memory of the present, but we know she was in Hell during this time. It's possible that Diabolos, displeased that she helped destroy the Leviathans, punished her once again by sending her back to 1795, but perhaps this time erased her memory (which would explain her rough treatment of Julia). This is a cold Angelique (she uses the name Valerie, btw), though she has an amazing change of heart (and her powers improve) at the end of the 1840 storyline.
