Sooo basically Charlotte is actually her and not a reincarnated lady, but you probs already guessed that. She went crazy in The mansion so G** brought her to another world (earth) but she was tricked by a demon to return. Dietrich ends up leaving the mansion but also losing his memory, and Charlotte stopped him from re-entering the mansion since he lost his memory. I believe the boy is Charlottes and Dietrich's (I don't remember much about this) but she does end up saying goodbye to her son when they leave the mansion. Charlotte eventually breaks the curse of the mansion and her body reverts to the time before she died, meaning that she was pregnant with Dietrichs child, and she runs towards Dietrich saying his name. Its a bit of an open ending because all we know is that Dietrich will fall in love with her again. The culprit to it all is Charlotte's brother. Because he wanted to see her suffer.  Lmk if you have any questions! I try to answer them based on what I remember