As the head, do I need to thank my wife and children, or is it enough that they know their responsibilities?

A leader who gives thanks nourishes love and spirit in the family; it does not weaken his authority. The Prophet ﷺ said: “Whoever does not thank people has not thanked Allah” (Sunan Abu Dawud 4811). People whose efforts are appreciated give more, willingly, not under compulsion. Say thank you specifically: for the cooking, for the work, for their patience. This teaches children to return kindness and makes the home a warm place. Expecting people to do their duties without a word of appreciation dries up the relationship. Start today with one sincere thank you to each family member. See everyday adab.