I'm not one to judge another's relationship. I've been through some crap and I know how it can go.…

I'm not one to judge another's relationship. I've been through some crap and I know how it can go. But.. This girl on my Facebook is making me so mad. She literally posts mad photos on Facebook, sharing them and saying some rude shit. She was saying she deserved better, calling the guy a pos, so crazy shit, obviously making it known to everyone on Facebook that he did her wrong. She didn't hide anything, talked mad shit about him to anyone who asked what's wrong, practically said he was abusing her mentally, called him a cheater and much more... This went on for like two months straight and then she started putting sad/angry pictures and saying stuff like she don't deserve to be so sad and shit.. Now, she just posted a picture that said "I can't even look at you without wanting to kiss you" and said in the caption "all I have is pictures but I still wanna kiss you!!" And I was thinking yay she found someone good! I went to comment how happy I was for her and someone else commented saying to stay strong and shit.. And I asked her if it was the same guy and she said yes... I feel like at this point she doesn't deserve that guy even if he is a cheater because she bad mouthed him so badly and spread all their business to the world, maybe he wasn't even that bad and she just was being dramatic to make him look like shit.. Even if he was bad, she shouldn't of blasted it all over social media. Literally, every post for so long was negative shit about him. She made herself look stupid in my eyes, but I'm not going to comment because it's my boyfriend like stepsister and I don't wanna cause problems.. But it makes me so mad when girls do that and then stay with the guy.. She blasts their relationship all over Facebook.. It just aggravates me. I feel like I'm part of the relationship now because I know so much just from her talking shit on social media..