I can only imagine how frustrated you are. With a different bio-dad you add a whole set of new family members into the pic, as well as a whole new support system. This changes the whole dynamics. Add in a different county all together, and you might as well forget it.
Have you talked to your SW about how things are going with the new baby? If the placement seems satisfactory, I doubt much will change. It may be that the grandparents have custody of the child and the mother is living there. This happened with one of my placements. Aunt got the baby and was in charge of the baby, but mom lived there as well. The aunt had to prove that she had licensed daycare while she was at work so the baby would never be left alone with mom.
The system is mind boggling. I'm sorry
