I have a friend who was a meth addict. We met in hospital - I was there for depression and intolerable side effects of medication and she was there to come off meth. She had a 5 year-old daughter.
After we left hospital, she went straight back on the meth and I didn't hear from her for about 6 months. She had another stay in hospital and since then she's been clean. Her daughter is now a teenager and has been living with my friend since the last time she was in hospital.
Maybe you can help your friend come off the meth. It's an extremely addictive drug, it's possible to get addicted after one try of it.