How do my son & I intoduce my Born my sister lives as my brother to people?

Well kudos for looking from both sides. I would keep looking to k for the answers to these questions. Being proactive in your inclusiveness is good, but remember that there is such a thing as being too supportive. It can be just as suffocating. On the whole I would say y'all are doing fine and keep it up! K is a lucky person to have you.