D.B.
D.,
I think you will do MUCH better in your posts if you put your location in the TITLE vs. in the body of the question. Not everyone on Mamapedia receives every single post, and they don't read every question they do receive. So, putting "Central NJ Low Income Housing" as the title would have gotten your question flagged by more people in that area or more who live elsewhere but have familiarity with NJ from living there before. So that's just a general hint for all questions going forward that are specific to your geographic area.
I understand your mother's feeling of worthlessness - that happens to most abused women and certainly those who have been out of the job market for a while. She's had a major number done on her self-esteem, having to be the slave to this man.
Your mother can do several things. The first is to work on putting her head back together, and that means counseling for her and for your younger sister, who has watched her mother be browbeaten during her own formative years. That's going to affect the way your sister chooses boyfriends and the way she allows herself to be treated. Your mother should contact the National Domestic Violence program (http://www.thehotline.org) for excellent legal advice and work strategies. It's free. She may have the wrong lawyer as well, I'm not sure. While Julie S. was very blunt and no doubt hard for you to read, she's correct that your mother's equity in the house is probably substantial. If your mother doesn't need to move out and into a secret location to be safe from her abuser, staying might be her best option. But the Hotline can help her with a variety of strategies and referrals.
That she got a job is a good thing. The state division of employment may have free courses to build up her skills in some marketable areas (computer skills, for example), and the public library may have some as well. I know she is working full time and raising a teen, but this is important. Your sister may also do well to take some courses in things not covered in high school, even if she is struggling to have a normal and drama-free life (which she should).
Your mother's husband may well be responsible for spousal support and maintenance on the home if his name is on the deed.
Even though your mother has an attorney, it doesn't hurt for her to talk to the Hotline to get additional support and legal advice, and perhaps referrals to lower cost attorneys or even may housing options. Please urge her to call. They can help her formulate a solid plan.