What should a girl do when facing her sister's strong rejection of her engagement after her father's approval, which has led to the deterioration of their relationship and negatively impacted her life and studies?

The Sacred Law calls for harmony and affection among Muslims, especially relatives, and the corruption of relations and the cutting off of kinship ties are forbidden. If the sister treats one with coldness and abandonment, she is in the wrong. The questioner should continue to attempt reconciliation, supplicate, and seek the help of those who hold influence to mend relations between them. If reconciliation proves impossible, she should try to forget the matter and focus on what benefits her in her religion and worldly life, while frequently remembering Allah, who removes worries, and not despair of reconciliation.