Is the girl considered at fault if she refuses to compromise her dignity, which the father of her fiancé has insulted, especially since her fiancé prefers his family over her despite his acknowledgment of his father's wrongdoing, and given that the fiancé's father does not wish to complete the marriage at this time?

The meaning of "تنازل" (concession/waiving) is unclear. However, if the suitor is a man of good character and religious commitment, it is advisable to hold onto him and agree with him regarding expediting or delaying [the marriage], as long as it does not cause harm. It must be noted that he is still a stranger to her, and it is not permissible for him to be alone with her or to speak with her without necessity. It is preferable to focus on setting a date for the marriage, reconciliation, and understanding. If the fiancée believes that matters will not be stable after marriage due to her family's dislike of her, there is no harm in breaking off the engagement, as it is better than divorce and discord after marriage.