Love this movie! Question on ending. Sorry if a repeat post/question

Hello,

I am new to the board and to IMDb. I love this movie and I know it is just that. However, I am curious to know what others think happened after the end. We know he gave his address to his "mom" on the top right-hand corner of the letter. I personally assume that they all kept in touch and became a "family" somewhat. But, what about them fighting for custody for Robert? What would the rights be? Do the adopted family have any rights considering the situation?

Allison