Hey kimbercares4u,
Meth is the big daddy of the drug world today. I'm a recovering crack addict and in outpatient rehab, my counselor, sayes that Meth is much, much worse. And Crack use to be the king of the drug world addiction wise. I've never heard of anyone who could kick Meth by themselves. I suppose anything is possible, but I doubt it. Encourage your friend to go into at least outpatient rehab (really needs inpatient probably) and to attend 12 step meetings - NA or CA. Valley is right about the whole family being made sick by addiction. Mom needs to either make her get help if she's under age or if she is old enough get out unless willing to get help. The family dynamics sounds unstable and the issues there are probably some of what this young woman needs to deal with to get and stay clean and sober.
Meth and Crack users can stop for a few days, even a couple of weeks at a time. But unfortunately that is about as long as it will last without some type of rehab and/or support system. She needs the support/understanding that only a recovering addict can give her. She also needs someone who will call her on her sh.. and know when she's bull....... The sleeping for days is part of the cycle with Meth/Crack addicts. They stay up for days and days using and then crash for days and days to recover. Then the cycle begins again.
Hope this helps a little. There is so much more we could say, but in the end your friend must admit she is an addict, that she is powerless over drugs and that her life is unmanagble. Then she must be willing to go to any lengths to get and stay clean. She must realize that one of three things is going to happen to her - Recovery - Institutitions (Jail) - Death. There are no alternatives. She must also hit bottom so to speak. When the consequences of her drug use get so bad that she will surrender completely then she can begin to heal and recover.