What would you do?

first of all im not asking this because im nosey or trying to get in someones business! I am concerned for this 7 week old baby!! My cousin and his girlfriend have a 7 week old baby, keep in mind they are ex- heroin addicts who have supposely been clean for 5 years, well the mother of the baby has been popping strong pain pills since the day the baby was born, she goes to her dentist and keeps getting refills and shes so high on pills she doesnt hear the baby crying while shes sleeping, also she doesnt feed the baby right, she props the bottle! This baby is 7 weeks old, im worried for the baby, and the mother is always reuring everyone she only takes these pain pills for her tooth ache, but that is getting old. Its been going on for 7 weeks now and shes always messed up! What should I do? tell department of children services, tell her how it is or what?