Pregnant younger sister...

My little sister is pregnant with a baby boy that I've begged her to move in with me so I can help raise him. Or allow me to adopt him. She's 20 she has no job has never been able to hold down a job this entire pregnancy she's not had a single job. She's struggled with drug addiction(meth) even while in her early pregnancy. She says she's been clean but I don't believe her. She doesn't know who the father is but THINKS she has it narrowed down to two guys. One of which is a married man with three children with his wife already. The second knowingly gave her chlamydia WHILE PREGNANT! She has lived in four separate states throughout this pregnancy and she's only just now 6 months along. Currently she's living with her brother so that him and his pregnant girlfriend can help pay for her kid as well. She has no excitement about her baby and even tries to hide her belly constantly and not mention him to anyone new. The family of her brothers girlfriend didn't even know she was pregnant until she had been there a month. It's crazy! She isn't ever going to settle down and that's not the life that baby deserves!! But she won't listen to me. I've filled out applications for her myself to try to get her a job and she refuses to follow through with any interviews or anything. She's my step sister but we've known each other for 18 years so we call each other sisters. I love her but that baby didn't ask to be brought in to this world.