Fostering my brothers kids..

Purple bee
So my brother just got out of prison. While he was in prison I called cps on one of his kids mothers cause they were clearly being mistreated and my sister and I agreed to split them up and her take the two girls while I take the boy. Well cps finally got involved and my brother unfortunately is on drugs again, or so we think. The kids are in the care of cps at the moment. Well my brother just called and said he needed my info so cps can contact and that I can take one of the kids like agreed. Which is fine. I'm holding on to my word. But when I told my husband he told me that we can't have another baby if I take one of the kids. Regardless I'm helping. Those babies need a better life, yet I'm heartbroken that because of someone else decisions the family I planned on having might not happen. Any advice? I just got a job promotion so financially in the near future we will be more than well off..And I'm not sure if it will eventually be permanent or not since the parent have no want to of changing.