The woman I want as my second wife is an employee under my supervision. What should I think about?

Make sure her consent is truly free, and handle the conflict of interest at work openly before going any further. When the man is her boss, a woman under him may find it hard to say no without worrying about her job. Give her room to say no without any consequence, and involve her wali from the start. Check your employer's policy on relationships between employees, and consider informing human resources so that her work appraisal is no longer in your hands. Your existing wife also needs to know; a marriage that begins quietly at the office easily gives rise to slander. See criteria for choosing a spouse.