Charles Franklin Allen in the 1880 U.S. census for St. Louis, MO, had five children listed.The older two are a mystery to our family. Charles H. Allen was age 20 and listed as a son of Chas. F.The daughter was Francis F. age 17.The remainder three are the children of Chas. F and Henrietta.Since Charles and Henrietta didn't marry until 1871, who is the mother of the older two and what became of them? My husband's grandmother was the last child, Mary Penniman Allen. The family never mentioned the two older children, to our knowledge.