Sister was molested, no one in family cares

So, my older sister Sam has a different dad, and through that she has four other sisters. Their mom Jessica married this guy Joe, and last year Sam wanted to go to Oregon. I couldn't go because of work so she took Joe cause he has family there. On their way back when she stopped at a rest stop to sleep, she woke up with Joe shoving his hands down her pants, and touching her breasts. She wigged out and started to drive home, deciding to just not sleep. I asked why she didn't kick him out of the car, but she can't really answer. Just too panicked I guess.

Anyway, as she's driving home he is jerking off next to her, keeps reaching over to try and touch her more. She threatens to stab him with her keys if he touches her again, so he just touches himself the whole way home.

So Sam tells me all this, o encourage her to tell all of her sisters. After all, there's toddler girls he's around every day and they need to know who he really is.

They don't care at all, the encourage Sam to forgive him and let him apologize. So naturally I am outraged. I want to go off, but Sam tells me not to. So its been almost a year, every time any if her sisters invite Sam to anything for the babies, Joe is there. She just ignores him, tries to not freak out for her nieces sake. So I still don't say anything.

Yesterday, Sam is at work and I guess they all show up, tell her the babies are in the car and to go say hi. So she goes, fucking Joe is sitting there. She calls our mom, and mom tells me what happened. I go down to her work and act like I didn't know anything was up. So she takes me into the back to talk to me and breaks down. Listen, Sam and I have been through a lot of awful horrible shit. I have only seen her cry twice in my life. So that got me. She said she's so upset she waited so long to get into contact with her dad and sisters and have them turn out like this. to be resubjecting her to her abuser again and again and telling her to forgive him. So I messaged all of them, including Joe's wife, sent them all an identicle message. Said that Sam is suffering and I cant believe they don't care. She was molested before and now its happened again. Exceit this time, her family, who is suppose to protect her, is willingly letting this fuck around her again and again. That its sub human to treat your family like that. That instead of asking her why she isn't around as much anymore, maybe they should look at their own actions. I went off, Joe's wife just sent me back a thumbs up emoji. So I sent her a message that said "I hope you sleep well at night knowing you'd rather be with a sex offender than be alone you miserable cunt"

So flash forward to today, one of her sisters sends me back a message saying I'm the most miserable and angry human she's ever met, and she hopes for my unborn child's sake I can learn to clean up my mouth and stop projecting my shit life on Joe. She said I need to grow up and stop being so angry.

I am hysterical. Not because I care what she says to me, but I am so upset for Sam. They literally just do not understand that this is wrong. They have zero interest in protecting Sam, they just want to protect Joe. And let him babysit their toddler daughters all the time. And tell me my kid is fucked cause I cuss.

I literally don't know what to do or how to calm down. I know this stress isn't good for my baby, I just dont know how to not be upset. I am devistated for my sister.

Please, any advice would be helpful.