Firstly her DH needs help. Call Jewish board or ohel and get him to therapy and medication right away. She should tell him she can no longer live like this and he must go for help. I think ohel has a team that can come into the house and help him get to agree to go for therapy
Let her apply to tomechi shabbos for food pkcagss. There are also other ways to get food depending on her neighborhood. Google your neighborhood and gmach and see what comes up. Masbia has a restaurant she can go to for dinner with the kids to get decent meals during the week.
Food stamps and Medicaid are also available if she qualifies for that help. There is also a program of help pay fro heating ( I don’t knwo much about it just that it exsists )
She has to break the cycle and she has to be strong inorder to raise her children right. If she doesn’t do things now it will effect her kids.
