Is it permissible for the husband to stipulate to his working wife that she bear her personal expenses in exchange for his approval of her work, knowing that her work is not essential and that the wife desires through it to secure independent money and gifts for her relatives?

The wife's maintenance and clothing are obligatory upon the husband, even if she is wealthy. However, if the wife agrees to waive some of her rights to maintenance in exchange for her husband allowing her to work under the legitimate Islamic guidelines, there is no objection to that.