The index for “Wills, Administrations, Guardianships and Adoptions of Highland County, Ohio (1805-1880)” by David and Jane McBride, copyright 1957, does not show Booker Brown or a Nancy Brown prior to 1834. If the McBrides didn't find anything it probably doesn't exist.
“Marriage Records of Highland County, Ohio (1805-1880)” by David and Jane McBride, copyright 1962, shows that a Booker Brown and Elizabeth Penington were issued a license on 23 Jan 1836.
Index for 1820 census shows Booker Brown in Paint Twp. He also voted there in 1821.