What is the ruling on a girl removing her hijab secretly upon reaching school and putting it back on when returning home to avoid her father's anger, and what advice is directed to her?

The hijab is an obligation upon the adult Muslim woman, and obedience to the father in wearing it is an affirmation of that. A girl removing her hijab in front of non-mahram men after reaching school is an act of disobedience and a sin, due to her negligence concerning the right of Allah and the right of her father. She must be advised and reminded of Allah's punishment, the benefit of the hijab, and warned against tabarruj (displaying one's adornments) and immodesty. A woman calling another woman is preferable, and a man calling (a woman) is permissible with controls. As for the niqab, it is obligatory according to the preponderant opinion, and its matter is less severe than that of the hijab.