Who’s right here?

So I’m 15, and I’m in 10th grade at school. Get ready for some high school drama people. So me and my friendship group (currently only of me and 2 other people at the moment) and we are known as ‘the nice ones’ in our school. So people like to take advantage of that. One girl, we’ll call her Ana decided we were too nice to say no and invited herself to join our friendship group. She’s not the nicest of people out there. And me and my friends were calling her a bitch and talking about her to each other. So she heard, called us a bitch and invited herself to someone else’s table. Who’s the bitch here?