if your boss let his wife to be your manager though she is not good at it,

Since it is the bosses wife, i would share my knowledge with her so the company wouldn't fail. If i saw no improvement in her learning the busines then i would need to talk to the boss. I wouldn't wait to long because i wouldn't want to see the company go bankrupt. Take care Sallyxu126.

Wow this is a good one, there are several factors to consider one, was this business created for her to manage or after thoughts, secondly does her a good business head but not the experience and finally how passionate are you about this business. It is possible that the business was created for her to manage and she may even be a shareholder in which case the boss had no choice in the matter .I am just saying this to help you understand that the blame may not all be due to the short sightedness of your boss. Could it be that she will learn the business in time, it just that she hasn’t been at the business long enough and with time she will get better.Are you patient enough to give her time to learn ? You could do one of two things if you are really passionate about working here. If you think there are no prospects that the business will grow under her stewardship, you could leave and go somewhere else. Or you could confront the boss and tell him your views. Tell him that your intentions not are insubordinate but you think he made a wrong choice and give him your reasons. In doing so be sure to provide alternatives, one of which would do make you her personal assistant if he is not to keen on removing her. Like I said this will depend on how passionate you are about this job and how well you know your boss