For simplicity's we're gonna use fake names.

So I'm in this friend group with the 3 of us (Allie (me), Gary, and Regina). Our friend, Regina, isn't a bad person. They're a good person. But lately, they've started becoming draining and almost mean girl-ish. They talk about their trauma non-stop whenever we hang out lately (they refuse to go to therapy). They're projecting their own issues and insecurities onto Gary. Not to mention they refuse to acknowledge that Gary is transgender (FTM; literally dead names them almost all the time and they've known for years Gary is trans). Then, last time we hung out for Regina's birthday, they made fun of my tattoo, laughing and said it looked like it was scarred (it's not). My friend Gary and I are trying to figure out how to talk about this with her. This has happened before and we've had to call her out on it. But lately it seems like it's starting to get out of hand again.

Any advice or feedback on this would be appreciated.