I agree with the marriage of Ruthie Jane Yawn and Richard Benjamin Luke. I think that I have missed the fact that Irvin was married twice:
(1) Elizabeth Smith who died in childbirth 1859 (Pollyann age 1 1860 census Coffee, Birds Mill, living next door to her father). Ruthie Jane Yawn born 1856 was her second child.
(2)married Sarah Moore/More 1860. They had two children before he enlisted. Sarah had a child before they were married; Mary Jane Moore.
Between the two (Ruthie Jane and Mary Jane), ages are not very consistent. Thanks for your input.