I agree that no contact with her is probably the best plan for now.
I strongly agree that CPS should be called about the daughter. (i'm not sure what they would be able to do but hopefully they could help! and if not at least it will put their names in their records incase things get worse for the daughter later.)
i know thats probably difficult emotionally but a childs well-being is far more important than anything else.
i hope things get better for you one way or another.