What do I need to do to get custody of my grandkids?

My grandkids are in foster care in a non jewish home. We are orthodox. Traditions are not being followed. I am their grandmother and need to get custody of them. I’ve approached child services who has guardianship of them and asked for custody but they say the kids are better where they are and if I want to pursue custody, I need a lawyer. How do I find a Jewish lawyer who is familiar with the local foster care agency? I have no criminal record and own my own house here in Houston. The kids could live here with me and see their real mom and dad under my supervision, if child services is worried about their safety.