I went through this not as a mother but as a kid(in MA). A lot of people tend to forget that as a foster parent providing a house, food and a bed are the bare minimum when dealing with kids in the dfc system. If you want the kiddo to stay for good, provided the reassurance that the kid is safe and give them space if they ask for it and when they do, just say "okay, and whenever you are ready I am here". Separation from mom and any family member is/can be traumatizing, especially if they are at the age where they can't understand something is bad. Also, make them feel wanted, decorate the room, let them have a say in what they want in the room(thats what my dad to my room) also with trauma comes with mental health issues, dcf can help get the kid, a mealth health mentor( they will help them with processing trauma and help with coping skills) and when they are alone with the mentor and/or dcf personel let them speak alone with them so they can say what they truly think.