The others have done a good job discussing your situation and how you might approach resolving the situation (i.e. backing down your interactions with her to "casually friendly", etc.)
Just a few random thoughts I had as I read this thread:
From your first post:
I was the one who reached out and suggested we spend one on one time getting to know each other and we connected on a friendly level. She doesn't seem to have many (well, any) friends and I felt kind of bad for her- I'm the kind of person who can make friends easily anywhere, so I didn't think twice about attempting to be friends. She seemed thrilled to have me want to be friends with her- and almost immediately started the oversharing and having odd boundaries.
I spend a lot of time thinking about introvert/extrovert interactions so this bit stood out for me. Maybe, being socially awkward, she IS looking for friends and doesn't know how to do it and you ARE doing her a favor by making the overture. However, this is not always the case. Perhaps she is an introvert, perhaps she felt obligated to accept your offer of friendship as your metamour, and then got confused when the type of "friendship" you wanted wasn't the "close/best friend/sharing everything" type.
I am an introvert, I don't WANT a lot of friends (two or three max, that I talk to once every few weeks/months is about right for me), but once I do let someone into my life I don't have any filters on private information ("oversharing"?) - it's kind of all-or-nothing. In my experience many extroverts look at their introverted acquaintances and "feel bad" for them and want to "fix them" by offering to befriend them and introduce them to people - essentially offering the type of superficial "friendships" that many introverts find so emotionally draining. No thank you! I would actually
rather spend the night at home by myself than go out socializing with you and all the "nice, fun" people you are friends with. We just want different things, socially, but we are not necessarily broken.
And I totally agree with MeeraReed when she says this:
Honestly, I think the key here is that she really IS socially awkward and struggles with communication. I would try not to take anything she says personally.
Her comment about the scarring on your labia from your rape--yes, totally inappropriate, but that's what socially awkward people do--they say totally inappropriate things and have no idea it was inappropriate. I have no idea WHY she said such a thing, except that if she's into edge play, maybe scarring is normal and/or a positive thing for her???? Socially awkward people have trouble empathizing with what other people are thinking/feeling and can only use themselves as a frame of reference.
Dude is, in my eyes, socially awkward verging on Asperger's. I love him but it drives me CRAZY that he literally can't conceive of the fact that other people can be bothered by things that wouldn't bother him. AND he cannot read the social cues that people use to let others know that they are uncomfortable so he just keeps going. I have learned to say to him: "Look, I understand that this topic doesn't bother you and you are not TRYING to piss me off but you are making me mad right now and we need to stop having this conversation."
I had more but I just realized I am late for work...