After some talking and some texting and another phonecall, we've determined that that phonecall wasn't even from my sister's friend. It was just a cruel, horrible prank call from probably a stranger.
It turns out that the caller initially called and said "This is Lauren and I'm in trouble! I need help!" Lauren is my sister's name. Since my mom answered and she knows Lauren would never sneak out and get in trouble (seriously, she goes to church like 4 days a week) so she checked in her room where she was, of course, sound asleep. My mom told the caller that Lauren was asleep in her bed, so the caller said it was "Lauren's friend from school" and when mom asked which friend the caller said "Who do you think?!" And my mom named off one of Lauren's friends, Naomi. The caller took her name and said she was Naomi after that point.
Looking back I'm sure the caller would have just taken any name mom had said.
Caller told my mom she needed to talk to Lauren at that point and mom refused because Lauren was asleep and talked to Caller for a couple minutes. Caller told her she got pregnant and that she was crying and blah blah. Mom said she needs to tell her parents and offered her to stay at our house if her parents kicked her out, then handed the phone over to me. Caller proceeded to tell me some fake BS story about how she was pregnant because she got raped by some guy she met on the Internet. The real Naomi has a boyfriend and would never cheat.
At that point since I thought Caller really was Naomi, I decided she really needed Lauren since they're like best friends. I woke up Lauren and gave her the phone, then went back to my room to read a book.
A whiiiiile later, Lauren came into my room and shoved the phone back at me, clearly shaken up, and mom and dad were standing near my door. Everyone was awake by now. Caller was still on the phone. Everyone left my room. I started talking to Caller again and she asked if she'd woken me up and blah blah, she asked if she got kicked out if she could sleep in my room with me. "I don't want to sleep alone, you know what I mean?" A little weird but I thought I was talking to a rape victim here. I told her to go to sleep and she asked me to give the phone to Lauren so she could say goodnight.
I went in to Lauren's room to see her sitting on her bed and my mom standing next to her bed. Lauren was crying. I have her the phone and she told Caller she was going to bed and hung up.
I thought Lauren was crying because she'd just learned her best friend was pregnant with a rape baby. She was actually crying because Caller had told her the baby daddy was actually her father and that he'd been raping her since she was twelve. Caller had then told her that she doesn't even like guys (which is crazy because Naomi is totally boy crazy) and that she's in love with Lauren and wants to make out with her and asked her if they could ever be together. This pretty much traumatized Lauren.
We texted Naomi, the real Naomi, asking if she was awake and she said yes, so we asked if she'd just called our home phone and she said no. Then we called her on the phone and she said that our text had woken her up. She sounded nothing like the Caller. We then let her go to sleep.
So as I type my dad is downstairs with a cop literally filing a police report about this.