Frustrating!!!

So my little sister (19) is in a terrible relationship with a man who tells her how much he hates her & puts her down. She is ugly to him. All of his money goes to them eating out or drinking at a bar. She has not finished school, has no drivers license, and no plans for her future. She doesn't take care of herself, physically or emotionally. 
HOWEVER, she keeps trying to get pregnant! She says she's had 2 miscarriages and just found out she is pregnant again. We keep telling her that having a baby isn't glamorous. It is a 24/7 job and babies aren't easy. She loses her patience with our kids within a few minutes. 
Well when she announced she is pregnant again, I feel like a terrible sister cause I am NOT happy for her at all. I feel she is being very selfish and if this pregnancy doesn't end up in miscarriage this poor baby will not have a good life. I just wish there was some way to get her to grow up and to listen. 😔 
I so hope she has children, but I feel now is not the time and this certainly isn't a good situation to bring a baby in