Is it obligatory for the questioner to prioritize performing the obligatory Hajj over helping her husband who is in financial difficulty, with the intention of performing a Hajj on behalf of her father, and is it permissible for her to perform Hajj with only one of her children, excluding the others, knowing that the money is only sufficient for two people?

Hajj is an immediate obligation. So, when a woman possesses the means to perform Hajj, she must hasten to do so, and she should not spend the money on other charitable causes. The presence of a mahram is not a condition for a woman's travel for an obligatory Hajj if the company is trustworthy. In such a case, she may perform Hajj alone. She may assist her husband with the remaining money if there is a benefit in doing so. If she wishes to avoid scholarly disagreement and take a mahram, and her husband does not agree, she may take one of her sons and be accompanied by whoever is more considerate to her. The husband's permission is not required for the obligatory Hajj, but it is advisable to seek his permission to appease him.