What can I do to help??????

I am sorry but there is nothing you can do. Her mother is on drugs or alcohol and is quite out of control. Normal people do not act like her. She need a rehab big time. She has to want to get help but if she doesn't she will not. She could possibly have a mental problem but what you tell doesn't sound like it. I am really hurting for her daughter. Her life is not fair and its not her fault. If her mother has an addiction quite often one or more of her children will have it tool Tell your girlfriend to not try drugs ever because some of them are addicting right from the first try.