Tilford James Kenan was my gg-grandfather. I've also been looking for more information on Robert and Josephine. It seems that the name was Kenion in the 1840 Indiana census and Kenyon in the 1850 Indiana census. As far as I can tell, it's been Kenan ever since.
Supposedly, Robert Kenan (Kenion) was born in Ireland. He married Josephine Pulliam on April or September 25, 1834.
Please let me know specifically what information you're after. I have a smattering of info on their children and on the children that belonged to her and Tilford Raborn or Rayburn.