Amita4ever, you really hit the nail on the head. Whoever wrote this about adoption obviously never researched anything about adopted people and their feelings. Obviously, different people who were adopted have different experiences, but the lah-dee-dah lackadaisical attitude portrayed here is ridiculous. It's like an American trying to write a serious novel set in Japan when their only knowledge about Japan and the Japanese came from reading Ranma 1/2.
Ha ha - I like your analogy :). Yeah. The presumptions made here were so superficial and shallow that it really ruined the end for me, but in the author's meager defense, including a more realistic reaction would have required more space, but as the one adapting the story they could have allowed for that.
Makes the plot feasible, but would she really have no reaction other than, "Oh? So I can be with you?" to find out that her entire life thinking she was these folk's daughter by birth was a lie?
I've known adopted kids. They love their adoptive parents, but being actually related is a big deal too. Just like the hero sought out his biological mom even though he had a family. Somehow, I just can't imagine her taking that news so lightly even if it had a happy side to it.