You were looking for a Jefferson Davis married to a Mary with a daughter Martha. Hopefully, you have already found them. I just visited the board today after an absence of several years.

Jefferson A Davis b1851 is the son of Jefferson Davis b1821 & Cartharine Standlee

He married Mary Morris. They appear in:
1900 Polo, Carroll, AR census
1910 Yocum, Carroll, AR
1920 Yocum, Carroll, AR
1930 Yocum, Carroll, AR

Their children include a Mattie J which is short for Margaret J rather than Martha. Mattie married "Fay" Humbard

Jeff A Davis and Mary M Davis are buried in Hale Cemetery in Carroll County, AR