Is it permissible for a girl to marry after her guardianship has been transferred to her brother, due to her father's refusal to marry her off because he is of a different nationality, knowing that the father is currently imprisoned?

The father forfeits his guardianship over his daughter if he prevents her marriage to a suitable suitor without a valid reason, and the guardianship then transfers to the next in line, such as the brother. However, if the refusal is for valid reasons, such as a difference in nationality or the unsuitability of the suitor's circumstances, the father is not considered to be obstructing the marriage (عاضلًا), and his right to guardianship remains. In this case, the brother is not permitted to marry off his sister without the father's permission. The imprisonment of the father does not nullify his guardianship if communication with him is possible. If the brother marries off his sister without the father's permission, and the husband has consummated the marriage, then the marriage is deemed valid, following the opinion of those who uphold this view. However, if the marriage has not been consummated, the matter depends on the father's approval of the marriage; if he approves it, it is valid, and if he rejects it, it is null and void. If the father tells his daughter, "Marry on your own by following the Hanafi madhhab (definition)," if his intention was non-approval, then the marriage is invalid. But if he intended to relinquish his guardianship, then the guardianship transfers to the brother, and the marriage is valid.