OK so how I think events go, more or less.
- Hannah is a shy, introverted child. She watches alot of tv and reads a lot of fantasy books, like Rapunzel. I don't think it's ever alluded she was abused in any way. At age 5 she meets Eve, her "twin" / imaginary friend. Eve lives in the attic in the house where Hannah lives with her parents. Both Eve and Hannah are names which are spelled the same backwards and towards (important because hannah mentions her name is, and it would be a hell of a coincidence if this other persons name also was, it's not because they are the same person)
- in her teens Hannah continues to be shy and introvert while Eve is the strong personality. They dates boys as Hannah but fuck them as Eve for example. Eve gets around but Hannah does not (she says she's not a slut in a video and how dare they ask that).
- at age 17 she meets her Prince (like in her fairy tale books), Simon. This is her first actual love and relationship so she wants Simon all to herself so Eve is pushes out of the picture for a bit as Hannah doesn't need her anymore. She gets pregnant with Simon which prompts them to get married and move on with her parents (Eve says in a video that she wasn't living with them and was going to move in later). She miscarriages the baby and her parents die from apparent mushroom poisoning, even tho her father works with mushrooms. Hannah is told by doctors that the miscarriage left her infertile.
- Hannah and Simon continue trying to get pregnant over the years but Hannah's shit tragic year pushes her over the edge and marks the return of Eve. Hannah disguises herself as Eve with a blonde wig and goes out to bars to play guitar sometimes, when one day Simon finds her, presumably while out for a drink himself. He goes to her but she's now Eve. Thy start a fucked up affair, presumably since Simon knows full well it's his wife. Hannah tells the cops many times Simon wouldn't cheat on her...and she's technically correct lol.
- Hannah / Eve gets pregnant, even tho she was told she was infertile (how can people still think they weren't the same person at this point, what are the odds the would both be infertile as eve clearly says they are in a video)
-Hannah has a tattoo of a apple and snake on her arm..you know, from Adam and EVE
-On her birthday Simon gifts her a unique handmade mirror, except it's not unique at all and it's the same thing he already gave her before. It's not clear if he thought he was giving it to the Eve persona or if he was trying to make her snap out of it, but this makes her cracking and she breaks the mirror and slashes his throat. There's a video with Eve describing this entire event, as if she's just looking on, if she was a real person why wouldn't she intervene? Why wouldn't Simon see her etc.
- There's no happy ending here. The whole game is her daughter Sarah (from the real pregnancy not the miscarriage of course) just wanting to know what made her mother do what she did. That she did it is never in question. You, the player, and by proxi Sarah find out your mom was a nutcase.
- Sarah knows what her mother did (the person on the phone at end asks her if she's happy to know why now, not how or who) so one assumes Hannah/Eve was either arrested, had Sarah in prison and had her taken away, or most likely sent to a mental institution, again had Sarah and had her taken away. There is no world where she raised Sarah or she would have no reason to come look for these tapes.
Some tidbits:
- Nothing that Eve says happens with Hannah can be taken for granted, it's all fight club style watching from outside of your body.
- Eve says she had the same diseases as Hannah, the same period time, that they are both infertile. When hannah gets in a fight and a black eye, she says hannah punches her so she also has a black eye. When hannah loses her tooth she says they rip out one if hers to match.
- how would a couple of 5 year old come up with this elaborate plan? How could they hide even their entire teenage life without the parents knowing. Hell if eve was real how couldn't the parents know about her lol.
- You never see Eve with short sleeves, only Hannah (for people saying one has a tattoo and the other doesnt)
There's a bunch more stuff that at the very least heavily indicates she was just crazy. It's a very classic split personality story. Feel free to argue it was actually a twin, I mean I didn't make the game so I can't be 100% sure, and in the end what matters is whatever theory you have, you liked it. And I loved it
So Eve was in the "attic" recovering from an STD while someone poisoned Hannah's parents with deadly mushrooms. Did Hannah do it? Eve had more motivation. Though she seems to be the more stable one.
That std probably caused her miscarriage, since, you know, they were the same person