So the actual diagnosis of psychopath is Antisocial Personality Disorder I will list all the signs that the websites list and give examples:

1 exploit, manipulate or violate the rights of others-

SD is an extreme manipulator, she manipulates people into dropping their friends, common phrases, "oh I am so glad *insert name* isn't sitting with us, she's getting so annoying, right?", attempting to get people to drop their friends that she percieves as a threat to her friendship in the group, trying to climb the ladder of popularity. She even did that to her friend and the friend's boyfriend in hopes to HOOK UP with that boyfriend. She will tell me "love you mom" thinking that it will get her on my good side, so that I won't suspect her of any mal intent. She has flat out TOLD me that if someone doesn't like her, she "makes them like her" by being around them all the time and being super nice to them.

2 lack concern, regret or remorse about other people's distress-

SD will see someone crying and put on a show of how sad she is too, trying to get the attention off the ACTUAL sad person. She will TORMENT people until they break, and then procede to act like SHE was the hurt party.

3 behave irresponsibly and show disregard for normal social behaviour

Her whole summer last year and into this school year, she's been friends with this girl for 3 years (her longest friendship EVER) and then tanked it all just to try to become more popular (it all backfired in her face, now she has 0 friends), she is friends with people for the sheer popularity, or power, or to try to hook up with their boyfriends, she refuses to eat in front of anyone, she will literally talk crap about me to my daughter (saying I called her fat to her face, that I believe that autism is caused by sitting on a tablet all the time) and then come in the room with me and "hang out" and talk to me (I pretend to be busy and leave the room)

4 have difficulty sustaining long-term relationships

Her LONGEST friendship was 3 years... but other than that, her friendships were about 1 year max. I always joked about how she changes friends more than she changes underwear (she'll be with us for the weekend and REFUSES to shower, and then say she only changes underwear when she showers, so she wears the SAME underwear from friday morning, all the way to at LEAST sunday night, but she only showers in the morning, so I am assuming, she wears them until monday morning. gross!)

5 be unable to control their anger

yes, she gets SO angry and tells herself lies to get angry.

6 lack guilt, or not learn from their mistakes

this girl has been making the SAME mistakes since i've met her... and has NEVER felt guilty. She lies, she steals, and lies to cover up the stealing, she mean, and hateful and takes the deepest digs at people (because she's fake nice and learns their weeknesses) and NEVER feels guilty about it.

7 blame others for problems in their lives

she has NEVER taken responsibility for ANYTHING she's ever done EVER. this past summer when DD17 broke her clip, and DD18 text DD17 about it asking if she broke it because SD is saying that she did, and DD17 test SD basically yelling at her for saying she broke it and telling everyone that she did. SD was trying to get DD18 in trouble for "eaves dropping" (when SD was literally TALKING TO DD18 about it) and when DH and I (i stepped in because DD18 was yelled at for eaves dropping and I wasn't about to have it) was trying to explain to SD that before she starts telling everyone that DD17 broke something that she should have confronted her. I even asked her, can you see that you are at fault even a little bit? she was quiet for a second (I thought she was thinking about it) she said no, that none of this would have happend if DD18 would have stayed out of her business. She STILL blames DD18 for all of that
Another time was when ALL SDs friends dumped her... she STILL blames them all.

8 repeatedly break the law

This one maybe not REPEATEDLY, but she has a few times, She has broken the law by stealing from the school fundraiser, stealing from her mother to cover it up, then stealing from the school fundraiser again, and then stealing from her brother, she stole from her mother again on a seperate occasion, but all this was covered up and looked over by her mother... she even had all her friends and family write the National Honors Society about what a wonderful honest, compassionate, trustworthy person she is.

9 Arrogance, a sense of superiority and being extremely opinionated

She is MUCH larger than my DD18 (who is overweight), but has the NERVE to talk about how big DD is and that she doesn't know who would want to see her "only fans" (DD was joking about starting one because she needed money) SD thinks she is so hot, and that everyone wants to hook up with her. she sees pictures of either DD17 or 18's friends and asks if they are single and wants to talk to them, acting as if they would be BLESSED to talk to her. TRYING to get any boyfriend of any friend to stop talking to her friend and tries to "console" the boyfriend when they break up. any time she hears ANYONE she is interested in breaks up she swoops in to "console" them. She even stooped as low to view someone's grandma dying as a chance to swoop in and claim them. She thinks HER opinion is the ONLY correct opinion. She give "ideas" on what should happen, and just goes with it, as if everyone agreed to it, when in reality EVERYONE thinks it sounds boring. and when we said "we didn't agree to it, she attempts tp convince us that its a great idea.