John and Lula supposedly had only one child, most likely stillborn. The story passed down in the family was that the child was buried in a shoebox, somewhere along the Platte River, Wyoming. True or not, no one alive knows. The two children (a son and a daughter) who were enumerated with them under the surname Barnum in the US Census for 1940 were apparently born of Lula's marriage to Alvin Kissick.
Vernon Paul says: [Theirs was] a happy, loving, and mutually caring union, from all I have ever seen or heard.