Foster daughters under age 13 leaving our home... How to handle family sharing / apple-ids

We have two foster daughters both under age 13 who are likely moving to a new home. While here we bought each of them an iPod that we anticipate they'll be taking with them. The kids have been on our Apple / iCloud / Family share for nearly a year now, and I'm looking for advice on how to handle this situation if the next home is unable or unwilling to transfer the children's Apple-Id. As I understand it, that would only leave me with the option of deleting their Apple-Ids, but I would really hate for the kids to lose all their apps / games / everything else. We can't be the first people to run into this. Any advice?