<p>Maybe its my legal training... I just don't see the situation as all that complicated. It's a relationship described by a contract. </p>
<p>Here's a analogy: think of Barnard/Columbia as a blended family -- Columbia is the father, Columbia College and SEAS are the father's natural children, and Barnard is a step daughter who tends to identify mostly with her mother... but the mother has married the father, and so she and her daughter are also part of his household. </p>
<p>Now it is possible that the father's natural children would reset their step-sister, but it is unlikely that the father would allow them to taunt and insult the step-sister. He'd demand that they treat the step-sister with respect, and emphasize that she was a full-fledged member of the family, even if she had come into it by virtue of the mother's marriage rather than birth. The step-sister would have full access to all the rooms of the house and all the food in the refrigerator, and for the most part be treated identically to the father's natural children. </p>
<p>I don't think anyone would think it strange or improper if the step-daughter called her step-father "Dad" or if she told others that she was a member of that family and that he was her father. And it would be perfectly acceptable and understandable that, depending on the context in which questions came up, she might identify one or the other or both her step-dad and her mom as her parents. In fact, in some circumstances it might seem quite rude if she made a big point of correcting someone who assumed that her step-dad was her father. </p>
<p>So that's how I see it basically.</p>