I've made my first contact with a "match" on familytreedna and thus begins a new adventure. Her line apparently connects to a dead-end line I have that immigrated from Ireland to the U.S. during the 19th century exodus. The surname of this gg grandfather and maiden name of this gg grandmother are so common on both sides of the Atlantic that I had filed this headache under "might not ever be answered". We both have these two surnames on our paper trees - I not knowing the birthplaces, parents or sibilings of either ancestor. She not knowing that any of her relatives had emmigrated to the U.S. We still have work to do to find paper records to support what we found in shared DNA. Although she and I share several DNA segments, she and my daughter share none. So, we sent off for a kit for my mother and I'll work on my niece to do the same. Meanwhile, I'll go bother the secretary at the parish where these gg grandparents married and had their children baptized and start digging around the census and passenger lists databases again since it might not be as daunting a task now that we, at least, have a clue about from where in Ireland the family hails.
Incidentally, all this is part of my family not the people who adopted me. In direct response to your question, I am the only adoptee in my family - of which I am aware. Although I found, reunited and even was legally adopted back by my natural parents...having had this experience I am sensitive to the fact that in this country, if you want an infant that matches you racially, and you have enough money, you can buy whatever you want and make everyone around you pretend you had a child. Six years ago, when I got involved on this tree, I had high hopes that it would highlight just how many adoptions there are, how they necessarily destroy one family in order to "create" another one, and how this process leaves each adoptee rootless and unattached to the rest of humanity. But, I see now that the adoptive parent side of the triad wins again in that this is no longer a vehicle for carrying that truth and there are plenty of adoptees that would rather pretend along with the status quo than face the frightening truth that they just don't know from where they came. And so, nothing about the way adoptions are conducted in the U.S. will change in the foreseeable future.
For all I care at this point, all of the 10,000 profiles I've created here can (and some probably will) be marked by other genealogists as having non-biological parentage without disconnecting the two people. Who cares at this point. I'll maintain an offline tree and continue to glean what, if any, accurate info I can find here and transfer it to my offline database as I do with any other source of potential information.