I erred in my first reply.It was late and I misread my own notes ... sorry!
Simon was not the son of Chesterfield, but instead the son of Chesterfield's brother Joseph.
Joseph S. Tadlock was the last son of Alexander Tadlock and Mary Ann "Polly" Bullington, and was born 5 Jul 1844 in Illinois.
Joseph married Catherine Overturf 24 Mar 1867 in Davis County, Iowa.Catherine was born Oct 1853, the daughter of Simon Overturf and Lydia M. (?).
Joseph died 18 Aug 1879, there in Wapello County.He and Catherine had six children, as follows: Zora Felicia (abt 1872) in Davis Co Simon Alexander (abt 1873) in Davis Co Susan (abt 1874) in Davis Co Steven Timothy (24 Jul 1876) in Wapello Co John Tilden (Dec 1876) in Wapello Co Mary Lydia (abt 1879) in Wapello Co
Charlotte appears in the 1880 census for Adams, Wapello County, Iowa as a widow (census in mis-listed as Fadleck) with the kids: