How can a father be convinced to accept the niqab in the future, knowing that he strongly rejects it and dislikes his wife wearing it?

Scholars have differed concerning the ruling on covering the face and hands, and the preponderant opinion is that it is obligatory. This ruling is connected to the girl reaching the age of taklif (accountability), one of its signs being the age of 15. The questioner must try to convince her father of this. If he insists on refusing, then there is no obedience to him, for there is no obedience to a creature in disobedience to the Creator. However, if she fears unbearable harm, then it is permissible to adopt the less preponderant opinion that allows uncovering the face. In this case, she should remain at home unless there is a necessity.