best friend issues

so my and my best friend let's call her Grace and I can not be separated. Latley based off of post on social media I see that she hangs out with people at school ( which is fine I don't care) we go to different schools. but then I see videos of them and pictures and I don't know if I'm just jealous ( i don't think I am) but she acts COMPLETELY different! she trys to act like a total bad ass. I don't want to use stereotype but I can't describe it any other way but trashy. with me she acts sweet and not like she does with others. She will be with me and one of her other friends will call and she starts talking differently and being really loud and talking how she is gonna fight someone. I don't know who the real her is. Any advise?