It is customary in the Black Church for the Pastor’s immediate family to be called the First Family of the many families in the local church. It is similar to the vocabulary of the First Lady of the United States, whose husband is the President. It’s also customary for members of that local body to be called brothers & sisters in Christ, the Son of God, and we are children of God. Those same members are the spiritual sons and daughters in the Faith. So when the Bishop introduced her as the First Daughter, it implied her position in the local body of Believers because although she's his biological daughter, she's also a spiritual daughter and the first of many because of her position. Everyone may not understand or agree, but historically, it has cultural significance. Those who know get it, while others may question, criticize, or crack jokes about it, but each culture has its practices that should be respected regardless of personal opinions.