Child molestation

(Kinda long)

My older sister and I have different dads. She lived with her dad till she was 15 (she’s 24 now) when she came to live with our grandma and the rest of my sisters and I due to her father molesting her for god knows how long. He was never charged or convicted and continues to live his life as if nothing happened. My sister still talks to him and has him in her life and visits him when she can. She also takes my 1 year old niece to visit him but doesn’t leave them alone. My family and I are in no way ok with this nor do we think that he should be involved in my nieces life or my sisters at all. He is a disgusting human being that deserves to rot in hell. My sister still wants him in hers and my nieces lives because (in her words) he’s still her father and my nieces grandfather and he deserves to be in their lives. She shuts me out anytime I try to talk to her about it so I can’t exactly ask her why she feels it’s ok to continue to bring this monster into their lives. If anybody has been molester/raped/sexually abused by somebody and still has them in their lives, can you please leave a comment and let me know your reason for keeping them around? I’m genuinely curious and want to understand where my sister is coming from. Thank you in advance to whoever decides to share their experience. I really appreciate it.

To add, I’ve asked her what she will do when my niece is old enough to want to stay with her grandfather for the weekend without her parents and my sister said she will just tell her she can’t and that she will deal with it when it gets to that point but she’s not going to worry about it right now.