From what I remember reading about the social sevices regarding the twins,was that " they were satisfied that they weren't in any danger " ( famous last words ) ,so therefore crossing them off the register.
Look what happened to Baby P and those like him where the parents either don't answer the calls,or they ignore any danger signals.
I would have had eyes in the back of my head with a woman like Sheila around,even though she held no responsibility for her illness,they have to be watched closely. Missing medication is a danger signal in schizophrenics. I know,,,,,,,I've worked with them.