We have come across many amazing people as they take care of children who have no homes or family to turn to. It's always heartbreaking to care for these children, see them reverse the negative environments they came from into a more positive one, but eventually a mother (and sometimes father) will have a chemical dependency that is briefly paused long enough to regain control of said children (sometimes for nefarious reasons like welfare checks).
That is why the best way to handle foster children is to outright adopt them from the hereditary parents. If one does not get a parent to relinquish their parental rights by signed contract, the availability to recover the child always exists. We have often found that an offer of a few thousand dollars to the mother (paid upon release) for signing a termination of rights and showing in court (one time) to verify said statements.
After the court hears testimony and takes the termination of parental rights into consideration, the foster child can be adopted. Upon adoption, the money must be paid or the contract and adoption may be nullified.
NOTE: It may seem ruthless to speak of foster children as an "asset" but according to the state, that is exactly what they are: movable property. When one thinks in these terms, it will be much easier to grasp that a contract can hold up in court as valid authorization to take the child without any recourse. Of course, it is best for one to give up a monetary amount for the child to have a valid contract by due consideration.