The tablets shes on can cause those side effects. I know that purely because my mum takes them too. I know if my mum hasnt eaten enough, or hasnt had alot of sleep, it can have the same effects. Im not however sayin shes not a drug addict. Im really not all that sure.
I know her husband may be an arse, but he's not holdin her head down to make her sniff the drugs, surely? I believe they are possibly as bad as each other, and I believe Brian should fight for custody of his girls, which im sure he will do. Those girls deserve better, even if its just until she gets herself sorted out. I never understood why he never got full custody before!