Is marrying a girl whom one's father rejected before his death considered an act of disobedience to him after his passing, given the strong desire to marry her due to her religiosity and good character?

If the father's reason for refusal of the marriage is acceptable, such as existing animosity between the two families, then his wish should be respected. However, if the refusal is for a personal reason of his own, and the woman is religious and of good character, there is no impediment to marrying her after his death, because disobedience (disrespect, literally "disobedience to parents") is not realized in this case. Filial piety continues after their death by supplicating for them, fulfilling their pledges, and honoring their friends, but it does not reach the degree of obligatory piety during their lifetime.