Insure your teen in care is gaining skills to independence. Budgeting etc. Approach your social worker to see if your teen can go on a confidence course or ask that the child be assessed to see if they really can live independently.
Insure your child has been able to rebuild healthy relationships with many different family members. Insure they have a big safety net should they fall.
A long time before your child even becomes a teen open a bank account. Put one dollar a week in it or as much as you can when ever you can. Even a piggy bank in your home can collect coins from time to time. Hold on to it and gift it to your child for when they come out but gift it by turning it into a food token from a super market or hold on to it for different times they might need your help. As a parent you might find it hard that they have not wanted to return completely to you but understand they still need you. It might be more in a practical sense but take the time to look carefully at their needs. DO NOT encourage them to seek money from exs or foster parents. Think what you can do.
Caregivers, work hard no matter how 'at home' your teen seems to be to insure they have a good knowledge of the real world. Insure they can cope. You might be just as willing to open the door for them when they are ready to go but do what you can to remain a positive supportive. Remember not all their genetic family may have issues and in fact some may even have some wonderful family members who can become great friends.
Last word for the social worker... Where would you be if you were alone in this world?