Just need some advice? its about friends

 ok so here is the begining of the stoy to the present. I went to high school with a girl we will Call faith. She was on the pom pom squad, but had a reputation for being a dirty slut or whore and would make up lies about her life just to get attention. But towards my senior year i became good friends with her, introduced her to my boyfriend at the time (now husband), she helped me through my pregnancy, came to my shower and helped my mom plan my baby shower, Helped me move in to our apartment we moved in at the time. then she came up to the hospital to see my son, held my son. But she started getting really busy so we lost all comunication.

 But like 2 years ago i contacted her and we talked just like old times. then she told me she needed some baby clothes because her best friend at the time had a baby boy and she was the godmother.  I agreeed and she paid me for the clothes. Then a week later this friend who we will call Abby found me on facebook. i accepted her friend request, we started talking, i went by her house, hung out with her.

 Then about one month ago Faith and Abby got in to a big fight because Abby's boyfriend fahter of her son was going to a party with a guy, but in reality he went over by faiths house and he didn't come home that night. So well we will say that Faith possibly had sex with him. And since that happened Faith has been posting horrible things about Abby, and Abby  is not the one to blame since she has been hurt. But again Abby posted some things about faith.  and well one day Faith posted that who ever is friends with Abby will be deleted. she knows i hang out with Abby and talk to her but she didn't delete me.

 And for Valentines day she posted she had a great valentines day, and Abby;s boyfriend was not home. So Abby and I are assuming he was over there, but neither will come clean. i even tried texting fatith to see if she would give me an answer so i can give it to Abby. But she didn't tell me anything.

 And last night i got a text from Abby saying to watch what Faith's posting on facebook. I told her ok, and have been. I asked her why and she said because her boyfriend was going over to  tell faith it is over between faith and him and whatever they are doing is done. And while he was over there Abby went to get a application for an aparment since this stuff has gone with her for 6 years. still nothing has been posted yet on  facebook.

 I am trying really hard to help Abby out since i connect better with her than faith, but for some reason i feel like i am in the middle of this.