exchange
An adoption exchange is an organization that assists in matching children in need of homes with parents wishing to adopt. As a rule, exchanges do not approve families for adoption, have children in their custody, or place children. However, they work closely with agencies that do these things, and perform other support and resource services, such as maintaining web sites featuring photolistings of waiting children. Families may register themselves or have their worker register them with one or more exchanges. Many exchanges are run by state governments, while others are run by non-profit organizations. In adoption, we also speak of the exchange of information between a child's caseworker and a family's social worker.

extended family
Extended family refers to relatives other than parents and siblings.