In her case they may take the kid the way cause the mother would be deemed unfit and the father would have to be at her side 24/7 in order for her to be watching th child. Unfortunatly dad cant afford to lose out on all his life because both chose to have a child this is almost a lose-lose sitiuation here some ideas though hunter...
~get a family member to help out~
~down here they have helpers who can come in everyday or weekly at no cost or little depending on the persons income!
~get her hubby to sit down and get in her face(have a good conversation) give her an ultimatum(as in she get help or he will take off with the child) just an example (there is so much more help available to a single parent!
~it is an offense in ontarios and quebec(i dont know about the other provinces but I could find out) to injure yourself or try and commit suicide it could result in hospitalization/jail time
~worst case call social service. It would be better to get the father to call so he can explain the sitiuation, if anything happens to that baby and (you or him didnt report what she was doing) you can actually be held resposible for her death in a court
good luck just keep drilling in her head what she is doing wrong without overdoing it but make sure you guys praise her when she is doing something right, when someone is in that state of mind it is almost as if they are a child themselve and the mind becomes fragile.