Adoption is a legal process where an adult (or adults) becomes the permanent parent(s) of a child who is not biologically theirs. The child becomes a legal member of the family and the adoptive parents have the same rights and responsibilities as biological parents. Following adoption, the biological rights of the parents are terminated.
The child is not treated as legally yours until the Court grants the order. In the interim, it's quite common for the intended parents to foster the child. This is an appropriate time to think about your Will. As the bond with the child develops, you will want to make sure they are cared for in the event of your death - both before and after the adoption order is granted.
You also ought to think about powers of attorney too, so someone has legal standing to manage your assets and decisions regarding your health if you are unable to do so.
Adoption Matters provides a lot of guidance for those thinking about adopting.
The Lawyer in London