Hi,
I think by 'publc' adoptions you mean waiting child (aka foster care) adoptions? These are adoptions conducted through state child care agencies where children have entered the foster care system either through voluntary or involuntary parental action - i.e. parents either relinquish to state care or they are removed from parents' care by state.
Waiting child adoptions as I understand them are primarily conducted through the states' child welfare agency. Prospective adoptive parents as I understand it undergo a homestudy and parenting/training classes.
In the majority of cases, bparents rights are terminated involuntarily and they do not have a say in where the child is placed, though I have heard of situations where extended family has a role.
A good link on waiting child adoption:
www.adopt.org
There are other board members with a wealth of experience on waiting child adoption. I hope they all chime in too!
Regina, AMom to Ryan Joshua Thomas