Persons visiting a "close relative" who is a national of Cuba, and persons traveling with them who share a common dwelling as a family with them, are authorized to travel to Cuba under a general license.
There is no limit on the duration or frequency of such travel to Cuba and Cuban Americans may now spend the allowable per diem i.e. currently up to $179 per day for hotels, meals, transportation while in Cuba visiting their family.
A "general license" is a provision in the U.S. regulations that, in and of itself, authorizes certain categories of travel to Cuba without having to apply for permission to the U.S. Treasury Department's Office of Foreign Assets Control, the agency that administers the U.S. travel regulations regarding Cuba.
A "close relative" is any individual related to a person by blood, marriage, or adoption who is no more than three generations removed from that person or from a common ancestor with that person.
For example, your mother's first cousin is your close relative, because you are both no more than three generations removed from your great-grandparents, who are the ancestors you have in common.
Similarly, your husband's great-grandson is your close relative, because he is no more than three generations removed from your husband. Your daughter's father-in-law is not your close relative, because you have no common ancestor.
For more information, see the official U.S. regulations regarding travel to Cuba (the Cuban Assets Control Regulations — 31 C.F.R. Part 515), available at www.gpoaccess.gov/ecfr/.