Is it permissible to accept the monetary amount offered by the father for Hajj, and does that diminish the reward of the pilgrim or the reward of his father, and is the husband entitled to take part of this amount?

The questioner's performance of Hajj on behalf of her father is valid if he is unable to perform Hajj himself due to an illness from which recovery is not expected. Regarding the expenses incurred by her husband: if it was a donation, then she should not take anything from her father. However, if it was not a donation and he intended to reclaim what he spent, then it is permissible for her and her husband to take only what they spent on Hajj, because Hajj is obligatory upon the one who delegates in terms of his wealth, and the expenses of the one who performs Hajj on his behalf are upon him. It is not permissible to take more than what was spent, because that would be considered a wage, which diminishes the reward, unless it was an independent gift from her father.