You should call. It seems like the niece is obviously overwhelmed and unequipped to take care of the baby. Both of them need help. The baby needs a home where it can be safe, and the niece needs help to cope with whatever she is dealing with. It's not like she will lose the baby forever. She can get the help she needs and then reapply for guardianship. If the baby where to die, I doubt the niece could recoup from that. I would call.