What is the ruling of Islamic law regarding a woman's insistence on working to support and help her family, despite the objection of her future husband, and regarding a man's stipulation that his fiancée not complete her studies when she has not yet completed them?

Working to help one's parents is a good deed, for which one will be rewarded. There is no objection to trying to convince the suitor to agree to your continuation in permissible work. However, if the suitor, who is religious and of good character, insists on you leaving your job, then it is preferable to accede to his request. Completing one's studies is not a justification for delaying marriage. It is permissible for a man to stipulate to a woman that she discontinue her studies, and if studies conflict with marrying a man of religion and good character, then marriage is more befitting for the woman, for the sake of her religion and her worldly life.