Nearly seven years ago my younger sister arranged for the open adoption of her then unborn baby. The arrangement from the very beginning was that she would have almost unlimited access to the baby, and there would be visits including extended family as well. Although we had all agreed to these terms, no one knew how things would evolve in time to come.
So here we are, almost seven years later. We have celebrated biological birth in the "adopted" family, birthdays, Christmases, among other activites and get-togethers.
The other day someone had remarked that the average length of contact between a birth-parent and the child is two years, and contact with extended family is almost unheard of.
We couldn't imagine having it any other way.