What is the ruling on a wife secretly taking her husband's money to recover her own money that he borrowed and did not return, or to take her maintenance?

A wife is permitted to take from her wealthy husband's money, without his knowledge, if he refuses to fulfill his financial obligation (debt) to her, provided she does not exceed or take more than what is rightfully due to her. However, taking from his money without his permission to purchase items that the wife desires is not permissible, unless what is sought falls under the category of the obligatory maintenance provided in a reasonable manner. If he is already spending on her in a reasonable manner, then she is not entitled to take anything from his money without his permission.