Is buying hair relaxers or a hair straightener for a girl who does not yet wear the hijab considered a sin, or does it fall under gradual upbringing, especially since she has been exposed to racism?

It is incumbent upon a Muslim to fear Allah, apply the teachings of Islamic law, and repent from transgressing Allah's boundaries. The daughter must hasten to wear the hijab and not delay repentance, for death comes suddenly. She must be wary of being among those whom the Prophet, peace and blessings be upon him, warned about: "the clothed yet naked." It is not permissible for the mother to assist her in displaying adornment by purchasing cosmetics. Rather, she must command her to wear the hijab and compel her to do so by all possible means, sometimes with gentleness and sometimes with strictness, for the mother is responsible before Allah for her negligence in forbidding her daughter from evil.