VERY tough decision

I'm going to make this story as short as possible. A year and a half ago, we found out my sister was using meth along with some other drugs, her husband called CPS and CPS took her two kids. She continued to so drugs and didn't cooperate with CPS requests. The father now has the kids and my sister is currently incarcerated for aggravated robbery. According to her druggy boyfriend at the time she was robbing people to sell stuff. I go and visit her every Wednesday and she asked if she can come live with me after she gets out,which might be soon because they were investigating her case. She swears up and down that she wasn't trying to rob the couple that she was looking for her phone her boyfriend threw out the window. For some reason unknown the couple got super irate and the husband went through my sisters window and she drove off with him attached. He eventually fell off down the road. She has been in jail since October. I go and visit her tonight as always but she will want an answer. I'll also find out what happened I court yesterday. She's always telling people that I am a bad sister because I couldn't take care of her two kids when CPS took them. My son was 6 months at the time and I was a first time mom and was not super confident in myself nor did we have the financial stability to take on two kids. She's a manipulator and is very two faced. I just don't know what I am going to say to her tonight and I wanted to get opinions. I would love to help her but I am not sure her heart is in the right place. When I visit her, she never asks about her kids, all she talks about is guys she's meeting in jail. I am also scared that if she's not ready to change that I'll be bringing that drama into my home, my family. I'm torn because I want to help her get right but I am scared, also financially we are not stable. She swears she'll get a job but she has no car and no GED, the likely hood of that is slim to none. We are also trying for our second and if she comes to live with us I know that will be put off. Please leave your opinion and vote.