Family who have moved away from Islam.

ASA. I’m a mother of three daughters. My mom wants me to keep close contact with my sister, who unfortunately has moved away from Islam. She is an alcoholic, but my mom doesn’t know. She also sins ( like curses, eats haraam, etc.). I really feel bad that she has taken this route and refuses to see how Islam is beautiful and guides you on how to live a peaceful life. We were raised in a strict home by my mom. My parents rarely got along and so my sister disliked our early childhood life. She relates that to Islam. I’ve tried to talk with her, tried to have her listen to influential scholars, etc., but she won’t accept anything. Now the issue is that my mom wants me and my daughters to be around her because my sister is lonely ( after her divorce). I don’t want my kids to be around such behavior as she drinks in front of them and does other sinful acts. Should I tell my mom about her drinking? I don’t want to hurt my mother because she doesn’t know that my sister drinks and does other things. My mother also takes out a lot of her frustration out on me, so if I tell her, she would start getting more angry at me. So When I try avoiding my sister, my mother gets angry at me. This is one of the many issues that are going around with the family. Alhamdulillah, Allah (swt) has blessed me with a loving and caring husband and children who support me. I pray to Allah (swt) that my sister sees the truth in Islam. Jazakallah khair. May Allah ( swt) reward you for helping me with my question. Sorry for making my post long.