Affiliate Marketing Secrets

My family is initially muslim, however we do not practice muslim and do not really affiliate with any particular religion. My sister who is 15 has been hanging with extremely religious upper clansmen seniors and she has lied to us saying she was going to birthday parties but really going to get “saved” or out with those friends to annoy the hell about people by convincing them whats right or wrong. My question is my mother wants me to talk to my sister to stop believing in it because she feels her friends brain wash her and i feel the same way but i think she’s at the point of no return and we can’t convince her to not believe in it yet we totally are against it. is there anything i can do?