Is the brother who fell out with his sister sinful for her refusal to comply with his prevention of her from going out due to some young men harassing her, and what should he do to complete the reconciliation without his sister taking the initiative to apologize?

The Shari'ah forbids a Muslim from abandoning his brother, and the longer the abandonment, the greater the sin. Whoever abandons his brother for a year is as if he has shed his blood. Moreover, abandonment causes a delay in forgiveness and the acceptance of deeds, and it is even more severe if it occurs between relatives, as it constitutes severing ties of kinship.

It is not permissible to cut off a sister because she is disobedient, unless cutting her off is a means to deter her from evil. The duty is to maintain ties with her, enjoin her to good, and forbid her from evil with gentleness and forbearance. Her going out for shopping or other purposes is not evil if she goes out modestly and does not expose herself to temptation. The fear that she might be followed is an illusion, and she should be alerted. It is also possible to accompany her when she goes out for her safety.