Texas Marriages, 1837-1973. W. E. Thomas and Malinda Louisa Williams. That this is a marriage record for Wilburn and Lula is based on the date, the place, the closeness of names (she is Louisa in the census), the lack of other records, and the lack of other candidates who fit this record. https://familysearch.org/pal:/MM9.1.1/F6BW-DMC
It may be possible to confirm family relationships with Wilburn by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Wilburn: