Think my sister might have psychological disorder

For readability, tried breaking it up into paragraphs:

As a bit of background, my sister has an eating disorder and alcohol and drug related problems...or so she says. I believe the eating disorder, but the way she talks about her drug and alcohol problems just go beyond what seems possible. Please, try and stay with me here.

My sister says that she was raped twice. One time at a party, and another time after she left a club in the city. Now, I would never in a million years have thought that I would question somebody saying they were raped, but soon these claims started to fall apart. It all started back in March. She was totally drinking too much, and was just acting strange. She ended up calling my mom to pick her up from her college, saying she was having awful stomach problems that were making it impossible for her to continue on in college.

She withdrew from all of her classes, and was put into the hospital. I do not now if they did any drug testing at the hospital. She clearly had an eating disorder, but my parents weren't yet open to believing this. Finally, she admitted and went home after two weeks in the hospital. Once she got home, she was drinking every night once everybody went to sleep. Then it went on to drinking during the day. My mom caught her drinking, and this is when my sister told me mom about the rapes. Right from there, my sister would change parts of the rape. She would say it happened at different times, different places. She went away to an inpatient facility for eating disorders and while there, the story of the last six months of her life got more detailed.

Now, during one of the rapes she was held at gunpoint. And it wasn't after she left the club, it was in the basement of the club in a bathroom where another man waited outside. I'm not going to go into detail, but just the way she explained it something seemed very off to me. Like every week the story kept changing to the point where it just sounded totally fake. I thought that maybe I was just being incredibly selfish, but then other members of my family came to me and said the same thing. I ended up facebook messaging this guy she said she met in the city who was from Ireland. To my TOTAL SHOCK, he said that he had never met my sister, that they had only spoken online. My sister had told me that she lost her virginity to this guy. It turns out that she had told him CRAZY things about my family. She said that my mom was an alcoholic (she does not drink at all, actually is against drinking) that my dad beats her (also NOT TRUE) and that I have slept with all her boyfriends. My sister has never had a boyfriend...and I have never slept with any guy she liked.

There was another guy she talked to online she claimed she met in the city who also had never been to america. The guy from Ireland told me he had heard about the rape too, and that it happened when she was a freshman. However, she told my family it was when she was a sophomore. He also said she knew who the person was, and went to the cops but the guy was a son of a cop so the police didn't believe her...even though she has always told our family she had no idea who did it and did not go to the police.

There are a ton of other things I could talk about. So many lies that she told to people online that it is starting to make me think she doesn't know fact from fiction. Like saying she was arrested, totally editing our older sister out of her life, making my parents out to be total psychos. The weirdest is the rapes though. Just because she told people online this totally different timeline. Like told the guy from Ireland she was raped as a freshman by someone she knows, but telling the family she was raped twice sophomore and junior year. It just doesn't make sense to me.

While she was away, she told my mom she was a heroin addict. My aunt is a nurse, and says the doctors at the hospital would have picked up on this right away. That there is no way she did heroin without the doctors knowing. She also has no scars or anything from needles. My sister claims she did heroin with a guy named quentin who she went to school with, but after asking her friends from school they all have no idea who he is. One of her friends said my sister mentioned a guy named quentin who used to come into where my sister worked, but that he for sure did not go to her school.

At this point I'm questioning if Quentin is even real. I know alcoholics and rape victims who experience trauma have a lot to get through, especially ones who have eating disorders, but there is just too much fantastical information here. Even now, she makes up lies to random people. Like yesterday she told someone in the art store that she finished art school a year ago and was an artist. When we walked away I confronted her on the lie and she said she had no idea what I was talking about. Anybody have thoughts on this? BTW, a doctor did say that she 'disassociates' but did not say DID.

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