How should my wife and I handle partnership responsibilities when more than 3 people are involved.

My wife is a partner in a not profit business w/ another woman. They have difficulty determining on who should be "in charge". My wife and I do not ume most of the leading challenges but do give some input. The main partner will often delegate responsibilities to us but if she does not like the task when completed she will redo the work herself which undermines us and makes look incompetent. How can we approach this situation?