For those that use mods... Little ms sam foster care mod you take in foster kids and then help find them adoptive parents by setting up a home visit etc. (the potential parents come to your home and you have your sim ask them questions etc and then decide if you want this sim to adopt the foster child) You can also adopt the child yourself after fostering him/her as well. They don't show up as a household member unless you adopt even though they live in your home (kinda like butlers do. If they run away you can call social services to return them)
