In the US, "The Kennedys" are generally considered to be the people who are descended from Joseph Kennedy and his wife, Rose. These include John F. Kennedy, Robert Kennedy and their children, etc. There are many people who have the Kennedy surname who are not members of "The Kennedys."
Robert Carlyle has 3 children
Robert Colbert has 2 children
Robert Wagner has 2 children
Robert Conrad has 8 children
Robert Mitchell has two children.
Robert Schumann has 8 children
Robert Downey Jr has 3 children
Robert De Niro has 6 children
He has five children
he had four children
Robert Lowell has 2 children