So I (21 f) live with my 3 roommates. I'll call them rosa (22f), emma(20f) and sara(26f) (not their real names lol)

Now, for some background, I moved into this room at the start of last semester, but that was the second year that the other three had started living with each other. The first year they were together, they were apparently very close, but Rosa had a falling out with emma and sara (mostly with sara, still on kinda friendly terms with emma) over veery stupid arguments that could've been solved with a 10 minute convo. For example it was shit like "your bag made too much noise while you were leaving", "you opened the windows when I was feeling cold" or "you put your pants on too loudly while leaving this morning" (I'm not even joking this was an ACTUAL argument). So basically the air has been very tense ever since I've moved in. I kinda felt bad for Rosa because she was left all alone in a 4-bed room, so I let her air her grievance out to me so she could get it out of her chest, but I've come to learn that Rosa isn't completely innocent either. She's very sensitive and if even the smallest "mistake" happens (the mistakes mentioned above), she either a) tells the other person in the most rude and annoying way possible or b) gets someone else to tell them off for it, even though she's a grown adult and can tell them herself. She once brought the dorms managers about shutting the windows instead of talking to the other two about it! That's not to say the other two aren't huge a-holes either. Now I've been dealing with their bullshit "problems" for like 6 months, but I think this might be the straw that breaks the camel's back

So tomorrow is emma's birthday, and she's started inviting a lot of people in front of rosa, but was leaving her out. Now in my head I thought that it was a really dick move considering the shit that's happened between them wasn't that severe, but ultimately it's not my birthday party so I didn't say anything. Now emma's mom called her to ask her about the birthday plans. Once emma explained that she was leaving rosa out, her mom kinda snapped on her, saying that she was being rude and inconsiderate. So, of course, emma had the brilliant idea to take sara with her to the stairway so they could both explain to her mom how much rosa sucks. And rosa overheard literally everything. So after that emma asked for my advice, and I was blunt with her and I told her it was a dick move to leave her out like that WHILE making the plans in front of her. I told her I'd invite her if I were in her shoes because she probably wouldn't accept anyway, but ultimately told her it was all her decision. So ofc, rosa accepted the invite out of pettiness because she heard everything that was said behind her back. She hasn't told emma, but she's told me that she'll accept. Now everything will probably be blamed on me if she accepts, even though I just gave out my opinion!

Now here's the thing: the story that you read above is a complete nothingburger, right? But here's the thing, being in this tense air for 6 whole months is really damaging my mental health (which has been really bad even without them), because I've kinda become the messenger between the 3 of them, and I can't just tell them that "hey, x said yall are a-holes!" No! I have to constantly find creative ways to give them the message without mentioning the messenger, and I'm neurodivergent so I'm going even more insane than a neurotypical person would. If I tell them that they have to stop telling me ts and just talk it out, then I kinda feel like I'm leaving Rosa behind. But at the same time, she was the one that brought this into herself by doing literally everything except talking it out like a 22 yo adult. And she's kinda been manipulating me into tell them, and it just sucks (not saying the other two aren't huge dickwads).

So, wibta if i told them to just talk it out with each other instead of telling me about it and shit-talking each othet? And If I'm not, how do you guys think I should tell them?

Sorry if this story's not entertaining, I just really need some advice lol